Hypergonadotropic hypogonadism in newborn males with primary testicular failure

Four infants with genital ambiguity but with apparent testes were given a gonadotropin-releasing hormone (GnRH) test and a human chorionic gonadotropin (hCG) test at age 3-12 days. The results were compared with those from 16 newborn males (aged 2 to 6 days) with minor genital anomalies; 9 with unilateral and 3 with bilateral incomplete testicular descent, 2 with surgically insignificant glandular hypospadias and 2 with penis length less than (means-2 SD) for gestational age. Treatment with testosterone resulted in clear phallus growth in all four patients. All four patients had elevated basal luteinizing hormone (LH) concentrations as well as an exaggerated LH response to GnRH; three of them also had an exaggerated follicle stimulating hormone (FSH) response. Thus in all patients the etiology of genital ambiguity was considered to be testicular. The testosterone response to hCG was normal in two of the patients but impaired in the other two. The steroidogenic response did not show any specific enzyme defect. We conclude that newborn boys with Leydig cell failure are clearly hypergonadotropic, the GnRH test is a more sensitive indicator of Leydig cell failure neonatally than the hCG test and normal testes greatly inhibit the secretion of both LH and FSH during the first week of life.     

Pituitary-gonadal axis in male undermasculinisation.

AIMS: To study the value of assessing serum concentrations of luteinising hormone (LH), follicle stimulating hormone (FSH), testosterone, and dihydrotestosterone (DHT) in patients with male undermasculinisation not caused by androgen insensitivity. METHODS: A retrospective study of a register of cases of male undermasculinisation (20 with abnormal testes, eight with 5alpha-reductase deficiency, three with testosterone biosynthetic defects, seven with Drash syndrome, and 210 undiagnosed). RESULTS: A human chorionic gonadotropin (hCG) stimulation test was performed in 66 of 185 children with male undermasculinisation. In 41 of 66 patients the dose of hCG was either 1000 U or 1500 U on three consecutive days. The rise in testosterone was related to basal serum testosterone and was not significantly different between the two groups. Testosterone:DHT ratio in patients with 5alpha-reductase deficiency was 12.5-72.8. During early infancy, baseline concentrations of LH and FSH were often within normal reference ranges. In patients with abnormal testes, median pre-LHRH (luteinising hormone releasing hormone) concentrations of LH and FSH were 2 and 6.4 U/l, respectively, and post-LHRH concentrations were 21 and 28 U/l. An exaggerated response to LHRH stimulation was observed during mid-childhood in children where the diagnosis was not clear and in all children with abnormal testes. CONCLUSIONS: The testosterone:DHT ratio following hCG stimulation is more reliable than the basal testosterone:DHT ratio in identifying 5alpha-reductase deficiency. During infancy, the LHRH stimulation test may be more reliable in identifying cases of male undermasculinisation due to abnormal testes than basal gonadotrophin concentrations.     

Pituitary-gonadal axis in male undermasculinisation

AIMS—To study the value of assessing serum concentrations of luteinising hormone (LH), follicle stimulating hormone (FSH), testosterone, and dihydrotestosterone (DHT) in patients with male undermasculinisation not caused by androgen insensitivity.
METHODS—A retrospective study of a register of cases of male undermasculinisation (20 with abnormal testes, eight with 5α-reductase deficiency, three with testosterone biosynthetic defects, seven with Drash syndrome, and 210undiagnosed).
RESULTS—A human chorionic gonadotropin (hCG) stimulation test was performed in 66 of 185 children with male undermasculinisation. In 41 of 66 patients the dose of hCG was either 1000 U or 1500U on three consecutive days. The rise in testosterone was related to basal serum testosterone and was not significantly different between the two groups. Testosterone:DHT ratio in patients with 5α-reductase deficiency was 12.5-72.8. During early infancy, baseline concentrations of LH and FSH were often within normal reference ranges. In patients with abnormal testes, median pre-LHRH (luteinising hormone releasing hormone) concentrations of LH and FSH were 2and 6.4 U/l, respectively, and post-LHRH concentrations were 21and 28 U/l. An exaggerated response to LHRH stimulation was observed during mid-childhood in children where the diagnosis was not clear and in all children with abnormal testes.
CONCLUSIONS—The testosterone:DHT ratio following hCG stimulation is more reliable than the basal testosterone:DHT ratio in identifying 5α-reductase deficiency. During infancy, the LHRH stimulation test may be more reliable in identifying cases of male undermasculinisation due to abnormal testes than basal gonadotrophin concentrations.
     

Spontaneous and GnRH-provoked gonadotropin secretion and testosterone response to human chorionic gonadotropin in adolescent boys with thalassaemia major and delayed puberty

To elucidate whether the cause of sexual maturation arrest in thalassaemia is of gonadal or pituitary etiology, 10 males with thalassaemia and delayed puberty and 10 with constitutional delay of growth and pubertal maturation (CSS) were extensively studied. Their spontaneous nocturnal gonadotropin secretion and gonadotropin response to intravenous 100 micrograms gonadotropin-releasing hormone (GnRH) were evaluated. Circulating testosterone concentration and clinical response were evaluated after 3 days, 4 weeks and 6 months of intramuscular administration of human chorionic gonadotropin (HCG) (2500 U/m2/dose). Thalassaemic boys had significantly lower circulating concentrations of testosterone compared to those with constitutional delay of growth and sexual maturation (CSS) at the same pubertal stage. Short- and long-term testosterone response to administrations of HCG was markedly decreased in thalassaemic boys. After 6 months of HCG administration 50 per cent (5/10) of the boys did not show significant testicular enlargement or genital changes. Despite the low circulating concentrations of testosterone, none of the patients had high basal or exaggerated gonadotropin response to gonadotropin releasing hormone (GnRH) stimulation. Luteinizing hormone (LH) peak responses to GnRH were significantly lower as compared to controls. Follicle-stimulating hormone (FSH) peak responses to GnRH did not differ among the two study groups. The mean nocturnal LH and FSH secretion was significantly decreased in all thalassaemic boys as compared to boys with CSS at the same pubertal stage (testicular volume). These data proved that hypogonadotropic hypogonadism is the main cause of delayed/failed puberty in adolescents with thalassaemia major. MRI studies revealed complete empty sella (n = 5), marked diminution of the pituitary size (n = 5), thinning of the pituitary stalk (n = 3) with its posterior displacement (n = 2), and evidence of iron deposition in the pituitary gland and midbrain (n = 8) in thalassaemic patients, denoting a high incidence of structural abnormalities (atrophy) of the pituitary gland. Moreover, in many of the thalassaemic boys, the defective testosterone response to long-term (6 months) HCG therapy denoted significant testicular atrophy and/or failure secondary to siderosis. It appears that testosterone replacement might be superior to HCG therapy in these patients. This therapy should be introduced at the proper time in these hypogonadal patients to induce their sexual development and to support their linear growth spurt and bone mineral accretion.     

Assessment of the gonadotrophin-gonadal axis in androgen insensitivity syndrome.

OBJECTIVE: To study the value of measuring serum luteinising hormone (LH), follicle stimulating hormone (FSH), testosterone, and dihydrotestosterone (DHT) in androgen insensitivity syndrome (AIS). DESIGN: Retrospective study of patients on a nationwide register of AIS. PATIENTS: Sixty one cases of AIS with androgen receptor (AR) dysfunction (abnormalities of the AR gene and/or abnormal AR binding) were divided into three age groups: infants, < 1 year old; children, 1-13 years old; and postpubertal, > 13 years old. MEASUREMENTS: Age, dose of human chorionic gonadotrophin (hCG) stimulation, pre-hCG and post-hCG serum testosterone values, serum DHT values, and serum LH and FSH values before and after LH releasing hormone (LHRH) stimulation. RESULTS: In 23 of 30 infants testosterone was within age related reference ranges; six were above this range. The median testosterone rise following variable dosage of hCG was 9.5 times the basal value. The increment was not related to the hCG dose, age, or basal concentration of testosterone. The median basal and stimulated testosterone:DHT ratios were 2.5 and 6.1, respectively. The median increment in DHT was 2.2-fold. Seventeen of 18 FSH and 11 of 19 LH measurements were within age related ranges in infants; in seven patients LH values were above the range. LHRH stimulation performed in 39 patients showed an exaggerated LH in all age groups. The FSH response was not exaggerated in children. CONCLUSION: Although a positive hCG test excludes biosynthetic defects of testosterone, an inadequate response does not exclude AIS. Basal LH and testosterone may not be raised during early infancy. An LHRH stimulation test might be useful for evaluating cases of suspected AIS presenting in mid-childhood.     

Smith-Lemli-Opitz syndrome: in vivo and in vitro study of testicular function in a prepubertal patient with ambiguous genitalia

The pathogenesis of the development of ambiguous genitalia reported in some 46,XY patients with Smith-Lemli-Opitz syndrome is not understood. Presumably, it is related to the 7-dehydrocholesterol reductase deficiency present in these patients. In this study we have evaluated testicular function, both in vivo and in vitro, in a 46,XY patient with ambiguous genitalia, reared as a girl. The diagnosis was based on clinical features, low serum cholesterol and high serum 7-dehydrocholesterol levels. Serum hormone values, determined during the first month of age, showed normal basal testosterone (1.95 ng/ml), LH (0.91 U/l) and FSH (2.51 U/l). However, serum testosterone did not increase after hCG administration (1.98 ng/ml). On the other hand, the patient had a positive biological response to exogenous testosterone (decrease in sex hormone-binding globulin serum levels). She was orchidectomized at the age of 33 mo. Testicular cells were dispersed and maintained in culture for 6 d. These cells showed a very good capacity to secrete testosterone into the culture medium (X +/- SD, 26.1 +/- 11.7 vs. 4.36 +/- 1.70 pmol/10(6) cells/24 h in a control group of testicular cells prepared from testes collected at necropsy). The patient's cells failed to respond to LH stimulation (18.6 +/- 4.0 pmol/10(6) cells/24 h), although they did respond to other stimuli. It is concluded that the severe cholesterol deficiency of this patient did not impair the capacity of the testes to synthesize testosterone. However, the LH/hCG receptor or its subsequent message was activated neither in vivo nor in vitro. This finding suggests that the foetal testes might have failed to respond to placental hCG at the time of male external genital differentiation. This failure could have been responsible for the ambiguous genitalia present in this patient.     

Male Gonadal Function After Chemotherapy in Survivors of Childhood Malignancy

Investigations of adult patients have shown that chemotherapy causes gonadal damage, but much less information is available about the impact of chemotherapy on gonadal function in children with malignant disease. At one time, being prepubertal during therapy was thought to confer some protection against chemotherapy induced gonadal damage. However, recent studies have indicated otherwise. We designed this study to assess gonadal function in 15 postpubertal males who had received polychemotherapy for a malignant disease during childhood and we compared them with 13 control adults males. The mean age of the patients at the time of the study was 18.2 ± 3.6 years (range 13.8–29.0), and when given chemotherapy treatment was 10.2 ± 3.0 years (range 6–16). At that time 12 were prepubertal and at the time of the study all were Tanner V. The mean interval from the completion of treatment until the study was 6.42 years (range 2.0–16.5). All patients had received polychemotherapy. We evaluated testicular size, sperm counts, LH and FSH after GnRH test, and testosterone levels. Puberty had progressed normally in all patients. We found no significant differences in testosterone and basal LH levels between patients and controls. However, we detected an appreciable difference in peak LH levels (P < 0.05) and in basal and peak FSH levels (P < 0.001). Seven patients had exaggerated LH response to GnRH, indicating dysfunction of the Leydig cells. The results of semen analyses were: 8 patients had azoospermia, 3 oligospermia, and 1 patient had a normal semen analysis. All patients with semen abnormalities presented a basal and peak FSH higher than the mean +2 SD of the control group. In summary, we found no evidence of gonadal protection in prepubertal patients. We found a high incidence of germinal cell damage, whereas Leydig cell abnormalities were found less often. An endocrine study of patients that have received chemotherapy is warranted. © 1995 Wi1ey-Liss, Inc.     

Hypothalamo-hypophyseal-testicular function in prepubertal boys with acute lymphoblastic leukemia following chemotherapy and testicular radiotherapy

Hypothalamo-hypophyseal-testicular function was studied in twenty-eight prepubertal boys with ALL in clinical and haematological remission. Eighteen were treated with combined systemic chemotherapy (24-36 months) and the other ten, who had testicular leukemic infiltrates, received chemotherapy (38-60 months) and testicular radiotherapy (2 000 rad). Plasma levels of LH and FSH were measured before and after stimulation with LHRH (100 micrograms i.v.) and plasma levels of testosterone before and after stimulation with hCG (1 500 IU/48 h/7 doses). In patients treated with chemotherapy alone, mean basal LH and FSH, mean responses to LHRH stimulation and mean testosterone levels after stimulation with hCG did not significantly differ from those of the controls. Five of these patients who had normal testosterone values after three doses of hCG had testosterone values below the normal range after seven doses. In patients treated with chemotherapy and testicular radiotherapy, mean basal FSH and mean responses to LHRH stimulation were significantly higher than those of the controls. Testosterone values after stimulation with hCG were low in three and very low in the other seven. In both groups of patients data from testicular biopsies were consistent with functional results. We conclude that chemotherapy causes slight testicular damage, but chemotherapy and testicular radiotherapy produce severe testicular damage in patients with testicular leukemic infiltrates.     

Hypothalamo-Hypophyseal-Testicular Function in Prepubertal Boys with Acute Lymphoblastic Leukemia following Chemotherapy and Testicular Radiotherapy

ABSTRACT. Hypothalamo-hypophyseal-testicular function was studied in twenty-eight prepubertal boys with ALL in clinical and haematological remission. Eighteen were treated with combined systemic chemotherapy (24–36 months) and the other ten, who had testicular leukemic infiltrates, received chemotherapy (38–60 months) and testicular radiotherapy (2000 rad). Plasma levels of LH and FSH were measured before and after stimulation with LHRH (100 μg i.v.) and plasma levels of testosterone before and after stimulation with hCG (1500 IU/48 h/7 doses). In patients treated with chemotherapy alone, mean basal LH and FSH, mean responses to LHRH stimulation and mean testosterone levels after stimulation with hCG did not significantly differ from those of the controls. Five of these patients who had normal testosterone values after three doses of hCG had testosterone values below the normal range after seven doses. In patients treated with chemotherapy and testicular radiotherapy, mean basal FSH and mean responses to LHRH stimulation were significantly higher than those of the controls. Testosterone values after stimulation with hCG were low in three and very low in the other seven. In both groups of patients data from testicular biopsies were consistent with functional results. We conclude that chemotherapy causes slight testicular damage, but chemotherapy and testicular radiotherapy produce severe testicular damage in patients with testicular leukemic infiltrates.     

Testicular descent: when to interfere?

Spontaneous descent of testes after birth can occur in up to 70% of cases, yet the factors contributing to it are still controversial. This study aims to evaluate factors contributing to spontaneous descent of palpable undescended testes. Eighty-four newborns with 126 palpable undescended testes (42 unilateral and 42 bilateral) were followed up for a period of one year to study the occurrence and time of testicular descent and its relation to gestational age, birth weight, uni- or bilaterality and levels of FSH, LH and testosterone. A total of 58 testes (46%) descended between 3 and 6 months. Spontaneous descent occurred in 10 premature patients (14 testes 63%) compared to 44 testes of full-term patients (43%). Descent occurred in 14 unilateral undescended testes (33%) compared to 44 (52%) in bilateral cases. In patients with spontaneous testicular descent there was postnatal peak of LH and testosterone at 2 to 3 months of age which returned to basal level at 6 months of age. In patients with permanent undescended testes the peak of LH and testosterone was very low and almost absent in some of them; no significant difference was found between the mean values of FSH in both groups. No spontaneous testicular descent occurred after the 4th month in the full-term group, whereas in the pre-term group spontaneous descent occurred up to 6 months of age. This study concluded that spontaneous descent of palpable undescended testes is closely related to the presence of LH and testosterone surge. Therapy of undescended testes should start at 4 months of age in a full-term baby and at 6 months of age in a pre-term baby.     

Testicular function after combination chemotherapy in childhood for acute lymphoblastic leukaemia.

We have assessed testicular function with luteinising hormone-releasing hormone (LH-RH) and human chorionic gonadotrophin stimulation tests in 44 boys previously treated with, or currently receiving, chemotherapy for acute lymphoblastic leukaemia (ALL). At the same time a testicular biopsy was performed in each boy and the morphology was studied. Histologically the chemotherapy appeared to damage the tubular system in particular, and the degree of damage was assessed by estimating the tubular fertility (TF) index which is defined as the percentage of seminiferous tubules containing identifiable spermatogonia. The mean TF index in all 44 biopsies was 51%. Only 2 of the 44 boys showed an absent or blunted testosterone response to human chorionic gonadotrophin. This suggests that Leydig cell function is rarely impaired by such chemotherapy and that most of the boys, similarly treat for ALL, will undergo normal pubertal maturation. Apart from the basal luteinising hormone (LH) levels in the prepubertal group which could not be compared, the median basal serum follicle-stimulating hormone (FSH), LH, and testosterone concentrations, the median peak FSH and LH responses to LH-RH, and the mean plasma testosterone responses to human chorionic gonadotrophin stimulation did not differ between the prepubertal, early pubertal, and late pubertal groups compared with normal boys of similar pubertal maturation. Three of 32 prepubertal ALL boys, and 5 of 12 pubertal ALL boys showed abnormalities of gonadotrophin secretion. The increased frequency of abnormalities of FSH secretion in the pubertal ALL boys compared with the prepubertal ALL boys could not be explained by more severe tubular damage in the former group. We conclude that moderately severe damage to the tubular system of the testis unassociated with Leydig cell impairment may not be detected in the prepubertal boy with current tests of testicular function.     

Increased LH and FSH secretion after cranial irradiation in boys

The effect of high-dose cranial- and craniospinal irradiation and chemotherapy on the gonadotropin-sex steroid axis was studied during different stages of puberty by measuring pulsatile secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone. The patients were thirteen boys who had been treated for malignant brain tumor residing well away from the hypothalamo-pituitary region. The median time to follow-up was 9 (1–16) years. The onset of puberty was early in the patients, median 10.5 years, compared to the average age for Swedish boys, which is at median 12.4 years. There was, before puberty, no significant difference in LH and FSH secretion between patients and a control group of normal boys. In early, mid- and late stages of puberty, however, LH and FSH secretion was increased in the patients overall, whereas testosterone secretion was maintained within the normal range in spite of signs of gonadotoxocity with small testicular volumes. These results indicate that the vulnerable parts of the gonadotropin releasing hormone (GnRH)-gonadotropin (LH, FSH)-gonadal axis are the regulatory system that determines the timing of pubertal induction and the gonads. The GnRH-LH, FSH-releasing neurons appear relatively resistant to cranial irradiation as they are able to respond with supranormal LH and FSH levels for long periods of time after treatment. Med Ped Oncol 29:280–287, 1997. © 1997 Wiley-Liss, Inc.     

HYPOPHYSO-GONADAL FUNCTION IN THE DIABETIC CHILD

ABSTRACT. 14 diabetic boys (five with a family history of diabetes and nine without) and 29 "short normal" boys were studied. A gonadal function test (2.000 IU of hCG i.m. for 3 days and plasma testosterone assay before and after the hCG administration) as well as an LH-RH test (50 μg i.v.) were carried out. While basal testosterone level turned out to be similar in the two groups of children, it was significantly lower ( p <0.01) after hCG than the mean value of the control group. This difference was mainly observed in those patients with a family history of diabetes. In the diabetic children, basal LH level was normal and the pituitary LH reserve was lower than in the control group. Both basal FSH level and FSH pituitary reserve were lower than in normal children. These data show that an alteration in the hypothalamus-pituitary-gonadal function is already evident in the diabetic child.     

Puberty in 24 patients with Klinefelter syndrome

Twenty four boys with Klinefelter syndrome, 18 of whom were diagnosed prepubertally, were observed until adulthood. Onset of puberty, as judged from testicular enlargement and pubic hair development, occurred between 11 to 14 years in the above 18 patients. By the age of 17 pubic hair, penile length and height had reached the adult stage in all patients, but arrest of testicular growth was noted at midpuberty, 13 years, with maximal mean (±SD) volume attained being 3.5±1.5 ml. The first conscious ejaculation was reported to have occurred between 13 to 16 years in 10 patients and in the remaining 4 between 17 to 18 years of age. Sperm counts obtained after the age of 18 revealed azospermia or severe oligospermia in all patients except one, who had a sperm count of 30×10⁶/ml. The hypothalamic-pituitary-gonadal axis, assessed by LH-RH and hCG stimulation tests, was found to be normal in prepuberty and during early pubertal stages. From mid-puberty the basal levels of plasma FSH and the response to LH-RH showed a gradual increase above the normal. Towards late puberty (>15 years) basal and peak levels of LH were above normal with a concomitant decrease in the basal level of testosterone and its response to hCG.These findings indicate that during childhood and early puberty function of the hypothalamic-pituitary-gonadal axis is normal in Klinefelter syndrome, allowing the onset of pubertal signs at the appropriate age, and that until late puberty there is a relative preservation of function in the testicular Leydig cells, permitting the normal sequential development of the androgen-dependent pubertal signs. The measurement of testicular testosterone reserve by means of hCG stimulation constitutes a useful aid in determining when and if testosterone replacement therapy should be instituted.     

Hormonal profile of puberty in South Australian children I

Serum follicle stimulating hormone (FSH), luteinising hormone (LH) and testosterone (T) concentrations in 118 boys aged 8 to 17.9 years were related to chronological age (CA), bone age (BA), genital development (G1–5+), pubic hair development (PH1–5 +) and mean testicular volume (MTV). A progressive rise in serum FSH, LH and T was noted in relation to CA, BA and all pubertal parameters studied. FSH showed an approximate twofold increase, LH an eight to tenfold increase and T a fourfold increase from pre-puberty through to full adult maturity. The FSH/LH ratio decreased with advancing CA, BA and pubertal development.     

How to evaluate gonadal function in the cryptorchid boy. Lessons from new testicular markers

In normal clinical practice, testicular evaluation in boys has relied on palpation and testosterone determination after hCG stimulation, which reflects the activity of interstitial Leydig cells. However, the most active compartment of the testis before puberty is the seminiferous tubule compartment, in which Sertoli cells proliferate and secrete anti-Müllerian hormone (AMH) and inhibin B. The recent development of commercially available assays for these two peptides has provided the pediatrician with excellent tools to assess the existence of functional testicular tissue in boys with no need for hCG stimulation. Serum AMH determination is also useful to assess testicular tissue mass and function in patients with intersex disorders. The determination of testosterone, its precursors and dihydrotestosterone, after hCG stimulation, should be reserved for situations in which Leydig cell function needs to be specifically assessed.     

Sertoli cell markers in the diagnosis of paediatric male hypogonadism

During childhood, the pituitary-testicular axis is partially dormant: testosterone secretion decreases following a drop in luteinising hormone levels; follicle-stimulating hormone (FSH) levels also go down. Conversely, Sertoli cells are most active, as revealed by the circulating levels of anti-Müllerian hormone (AMH) and inhibin B. Therefore, hypogonadism can best be evidenced, without stimulation tests, if Sertoli cell function is assessed. Serum AMH is high from fetal life until mid-puberty. Testicular AMH production increases in response to FSH and is potently inhibited by androgens. Inhibin B is high in the first years of life, then decreases partially while remaining clearly higher than in females, and increases again at puberty. Serum AMH and inhibin B are undetectable in anorchid patients. In primary or central hypogonadism affecting the whole gonad established in fetal life or childhood, all testicular markers are low. Conversely, when hypogonadism only affects Leydig cells, serum AMH and inhibin B are normal. In males of pubertal age with central hypogonadism, AMH and inhibin B are low. Treatment with FSH provokes an increase in serum levels of both Sertoli cell markers, whereas human chorionic gonadotrophin (hCG) administration increases testosterone levels. In conclusion, measurement of serum AMH and inhibin B is helpful in assessing testicular function, without need for stimulation tests, and orientates the aetiological diagnosis of paediatric male hypogonadism.     

The effect of testicular irradiation on Leydig cell function in prepubertal boys with acute lymphoblastic leukaemia.

Testicular function was investigated by the luteinising hormone releasing hormone (LHRH) test and a three day human chorionic gonadotrophin (HCG) test in 11 prepubertal boys with acute lymphoblastic leukaemia (ALL) who had received 2400 rads of fractionated radiation to their testes after relapse at this site. The results were compared with an unirradiated control group. Basal and peak testosterone values after 1000 units of HCG were significantly lower in the irradiated patients than in the control group. Peak follicle stimulating hormone (FSH) values after 100 micrograms LHRH were significantly higher in irradiated boys, but there was no difference in either basal FSH or basal and peak luteinising hormone values. The findings suggest that the ability of the Leydig cell to produce testosterone--as detected by the HCG test--is appreciably reduced after irradiation and that tubular dysfunction in prepubertal boys may sometimes be predicted by a raised FSH response.     

Extreme Tall Stature in a Japanese Boy with a 48,XXYY Karyotype

We report an 18-yr-old Japanese boy with a 48,XXYY karyotype and extreme tall stature (194 cm). A GnRH test at 12.5 yr of age showed hypergonadotropism (LH, 4.2 → 72.2 mIU/mL; FSH, 28.9 → 61.7 mIU/mL), and an hCG test at 15.5 yr of age revealed a normal testosterone response (1.67 → 4.08 ng/mL). The tall stature is remarkable, because the mean adult height of Caucasian 48,XXYY patients is 181 cm. Although the underlying factors for the tall stature are unknown, this report indicates an association of the 48,XXYY karyotype with marked tall stature.     

HCG stimulation in children with cryptorchidism

Fifty-eight children with cryptorchidism have been given hCG stimulation testing, 31 with bilateral cryptorchidism, 22 with unilateral, and 5 with prior unsuccessful orchiopexy. Hormonal studies were carried out prior to and following stimulation. In bilateral cryptorchidism, bilateral descent was observed in 32 percent of cases and in unilateral, the success rate was 55 percent. From their data, the authors concluded that hCG is not indicated if patients present elevated LH and FSH levels or if the basal T levels are in the pubertal range. In the other subjects, the hCG test will permit the determination of the presence or absence of testosterone production and in some cases it results in testicular descent. Finally, in cases of failure that require surgery, the hCG will stimulate tissue growth enhancing the success of orchiopexy.