5alpha-reductase 2 gene mutations in three unrelated patients of Greek Cypriot origin: identification of an ancestral founder effect

INTRODUCTION: 5alpha-Steroid reductase deficiency (5alphaSRD) is an autosomal recessive enzymatic deficiency. Mutations in the 5alpha-steroid reductase type 2 gene (SRD5A2) result in male pseudohermaphroditism caused by decreased dihydrotestosterone (DHT) synthesis--a key hormone of virilization of male external genitalia. AIM: To study for the first time patients from the Greek Cypriot population, describe their clinical characteristics, and identify the genetic mutations of the SRD5A2 gene. PATIENTS AND METHODS: Three unrelated patients with 46,XY karyotype born with ambiguous genitalia were examined. Patient 1 was raised as a girl and was diagnosed with partial androgen insensitivity syndrome, based on the clinical picture and incomplete laboratory investigation at the age of 4 years, and underwent gonadectomy. For this patient sequencing analysis of all five exons of the SRD5A2 gene and exons 2 to 8 of the androgen receptor (AR) gene was performed. Patients 2 and 3 were also born with ambiguous genitalia. The hCG test for these two patients was informative of 5alphaSRD, as it showed elevated T/DHT ratio after stimulation. Despite genetic counseling, both families decided to raise their infants as females because of severe under-virilization. Sequencing of the SRD5A2 gene was also completed for both patients. RESULTS: No mutations were found in the AR sequence for patient 1. Patients 1 and 3 were found homozygous for the mutation A/G at splice junction intron 1/exon 2 and patient 2 was found heterozygous for the same A/G substitution and also heterozygous for an additional mutation, Pro181Leu, in exon 3. CONCLUSIONS: The same mutation in the SRD5A2 gene was identified in three unrelated patients, in both homozygous and heterozygous form. This splice mutation was previously reported in Turkish patients. This underlying genetic abnormality may be characteristic for the Eastern Mediterranean region and is likely due to an ancestor effect.     

Combined 21-hydroxylase and 11beta-hydroxylase deficiency: patient report and molecular basis

A female newborn (46, XX) with ambiguous genitalia was initially diagnosed by biochemical criteria as having classical congenital adrenal hyperplasia caused by 11beta-hydroxylase deficiency. Shortly after effective treatment was administered, she developed a salt-wasting crisis with severe electrolyte imbalance. DNA analysis revealed a homozygous splice mutation in the second intron of the CYP21 gene, for which both parents were heterozygous. No mutations were found in the entire CYP11B1 gene, thus proving that the 11beta-hydroxylase deficiency was not caused by a gene mutation but rather was a secondary event, possibly due to androgen suppression of 11beta-hydroxylase activity.     

Mutational Analysis of Androgen Receptor (AR) Gene in 46,XY Patients with Ambiguous Genitalia and Normal Testosterone Secretion: Endocrinological Characteristics of Three Patients with AR Gene Mutations

The prevalence of abnormalities in androgen receptor gene (AR) among patients with ambiguous genitalia is unknown. Moreover, endocrinological data from prepubertal patients with AR mutation are very limited. Thus, the aim of this study was to examine the prevalence of abnormalities in AR among patients with both ambiguous genitalia, which was defined as a combination of two or more genital abnormalities (i.e. hypospadias, microphallus (penile length < 25 mm), hypoplastic scrotum, bifid scrotum, undescended testis) in this study, and normal to elevated T levels. We also compared the endocrinological data of prepubertal patients with AR mutation and ambiguous genitalia with that of those without the AR mutation. We screened 26 Japanese prepubertal 46,XY patients (five from three families were included) with both ambiguous genitalia and normal to elevated T levels. Mutations in AR were found in three (two of the three were related). Among the 23 patients without mutation in AR, the steroid 5-alpha-reductase 2 gene (SRD5A2) was also examined in eight patients with elevated T/dehydrotestosterone ratio after the hCG (>10) or with undervirilized family members. No mutation in SRD5A2 was found. Characteristics of the three patients with mutation in AR were compared with the 23 patients without mutation. In two patients, basal T levels (0.3, 0.2 ng/ml) and peak T levels after the hCG tests (8.3, 8.5 ng/ml) tended to be higher, and the peak LH/ peak FSH ratios after the GnRH tests (4.6, 4.0) were higher than in patients without mutation, at the ages of 1 yr and 9 mo and 3 yr and 8 mo, respectively. In conclusion, an abnormality in either AR or SRD5A2 was not common among patients with ambiguous genitalia and normal testosterone secretion. Elevated peak LH/peak FSH ratio (≥4) after the GnRH test in addition to detectable basal T levels and elevated peak T levels after the hCG test may infer AR abnormality in prepubertal patients with ambiguous genitalia at the age of one and over, although further study is needed, because our data were limited.     

Early diagnosis and management of 5 alpha-reductase deficiency.

Two siblings of Pakistani origin, karyotype 46 XY, were born with predominantly female external genitalia with minute phallus, bifid scrotum, urogenital sinus, and palpable gonads. The older sibling at the age of 8 days showed an adequate testosterone response to human chorionic gonadotrophin (hCG) stimulation. The diagnosis of 5 alpha-reductase deficiency was made at age 6 years when no 5 alpha-reduced glucocorticoid metabolites were detectable in urine even after tetracosactrin (Synacthen) stimulation. In the younger sibling the diagnosis of 5 alpha-reductase deficiency was provisionally made at the early age of 3 days on the basis of high urinary tetrahydrocortisol (THF)/allotetrahydrocortisol (5 alpha-THF) ratio and this ratio increased with age confirming the diagnosis. Plasma testosterone: dihydrotestosterone (DHT) ratio before and after hCG stimulation was within normal limits at age 3 days but was raised at age 9 months. Topical DHT cream application to the external genitalia promoted significant phallic growth in both siblings and in the older sibling corrective surgery was facilitated. In prepubertal male pseudohermaphrodites with normal or raised testosterone concentrations, phallic growth in response to DHT cream treatment could be an indirect confirmation of 5 alpha-reductase deficiency.     

Incomplete androgen insensitivity syndrome. Difficulties of diagnosis and management

A familial form of incomplete androgen insensitivity syndrome (AIS) is reported. The index case was first seen at 9 months of age for ambiguous genitalia. Diagnosis of AIS, suspected but first discarded on the basis of an androgen sensitivity test, was finally made at puberty on the discordance between poor virilization and elevated levels of both testosterone and LH, a florid gynecomastia, and the exclusion of any enzymatic defect in testosterone biosynthesis of 5 alpha-reductase deficiency. Androgen receptors in public skin were within the limits of normal for total number, with normal affinity. Familial occurrence included 2 first cousins born 7 and 10 years later, a maternal grand-uncle with similar ambiguous genitalia, and a maternal uncle with the gynecomastia-preserved fertility syndrome. This case report illustrates the heterogeneity of AIS in a given family and the difficulty of and early positive diagnosis in a newborn presenting with sexual ambiguity.     

Choice of gender in 5alpha-reductase deficiency: a moving target

Steroid 5alpha-reductase deficiency is a rare, male-limited autosomal recessive disorder caused by mutation in the SRD5A2 gene resulting in a deficiency of dihydrotestosterone (DHT) during fetal development. Here we report an affected 46,XY adolescent who was born with incompletely virilized genitalia and was raised in the female gender. At 12 years of age, the patient requested feminizing genital surgery. Surgery was withheld and psychiatric counseling was instituted. At 14 years of age, the patient's gender identity and role appeared to be in transition from a female to an increasingly male gender. This case demonstrates that in patients with disorders such as 5alpha-reductase deficiency, in which significant prenatal androgen exposures are combined with postnatal virilization, adult gender identity and gender role may be a dynamic process that is not complete until well after adolescence.     

A Case of Female Pseudohermaphroditism Caused by Aromatase Deficiency

Female pseudohermaphroditism is caused by several etiologies. Here we report a case of aromatase deficiency who showed ambiguous genitalia and maternal virilization during pregnancy. The mother had noticed her own virilization from 16 wk of gestation without androgen exposure and had low urinary estriol levels (5~10 μg/ml at 35 wk of gestation). At birth, the patient presented severe virilization (Prader V), and was assigned as a male with a micropenis and unpalpable testes but the patient had a normal female karyotype and a uterus and cystic ovaries found by magnetic resonance imaging. The patient had a increase in serum 17α-hydroxy progesterone levels (basal 4.9 → 37 ng/ml after a single 0.25 mg/m² infusion of ACTH), but the increase in adrenal androgen was not sufficient to virilize the external genitalia. Dehydroepiandrosterone, 17α-hydroxy pregnenolone and deoxycorticosterone were within the normal ranges. These findings suggested a diagnosis of nonadrenal female pseudohermaphroditism. From the clinical features and biochemical data, we endocrinologically diagnosed her as having an aromatase deficiency. The aromatase gene is now under investigation for definite diagnosis. We finally agreed that aromatase deficiency should be suspected when both the mother and the newborn have been virilized.     

Practical approach to steroid 5alpha-reductase type 2 deficiency

The aim of this article is to review the literature on steroid 5alpha-reductase type 2 deficiency (5α-RD2) to provide clinicians with information to guide their management of patients with this disorder. The 5alpha-reductase type 2 is encoded by the 5alpha-reductase type 2 gene (SRD5A2) on chromosome 2 and is predominantly expressed in external genital tissues and the prostate. Mutations of the SRD5A2 gene leads to an uncommon autosomal recessive disorder affecting sexual differentiation in individuals with 46,XY karyotype; their phenotype can range from almost normal female structures to a distinct male phenotype with ambiguous genitalia at birth. These phenotypes result from impaired conversion of testosterone to dihydrotestosterone due to mutations in the SRD5A2 gene. Patients exhibit virilization at puberty without breast development, which is often accompanied by gender identity change from female to male. More than 40 mutations have been reported in all five exons of the SRD5A2 gene. Phenotype–genotype correlations for 5α-RD2 have not been well established. The newborn phenotypes of male pseudohermaphrodites with 5α-RD2, partial androgen insensitivity syndrome (PAIS), or 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3) enzyme deficiency may be indistinguishable. We conclude that steroid 5α-RD2 should be included in the differential diagnosis of newborns with 46,XY DSD. It is important that the diagnosis be made in infancy by biochemical and molecular studies before gender assignment or any surgical intervention because these patients should be considered males at birth.     

Case report: WT1 exon 6 truncation mutation and ambiguous genitalia in a patient with Denys-Drash syndrome

Denys-Drash syndrome is a rare genetic disorder featuring the triad of congenital nephropathy, Wilms tumor, and intersex disorders (XY under-virilization or XY female). Denys-Drash syndrome is associated with constitutional mutations in the Wilms tumor suppressor gene WT1. Unlike WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) syndrome, with its complete deletion of one copy of WT1, Denys-Drash syndrome is generally caused by a dominant-negative mutation. We present a new case of Denys-Drash syndrome in a patient initially diagnosed with XY ambiguous genitalia/partial androgen insensitivity syndrome, who was found to have a novel nonsense mutation in exon 6 leading to a stop codon and hence a truncated protein. Based on lessons learned from this patient, the diagnosis of Denys-Drash syndrome should be considered in the presence of ambiguous genitalia and partial androgen insensitivity.     

A novel point mutation in the hormone binding domain of the androgen receptor associated with partial and minimal androgen insensitivity syndrome

Mutations in the coding sequence of the androgen receptor (AR) gene result in a wide range of androgen insensitivity syndromes (AIS). We report an extended family in which at least five male individuals in different generations suffer from partial AIS. The index patient presented at birth with ambiguous genitalia; the karyotype was 46,XY and subsequent sex assignment male. Elevated stimulated testosterone (T) and normal baseline gonadotropins were found. Family history revealed four additional adult males affected with various abnormalities of their external genitalia. Molecular analysis of the coding sequence of the AR gene revealed in all a novel point mutation in exon 6, changing threonine to isoleucine at codon position 800 in the hormone-binding domain. We conclude that phenotypic variations in mild AR defects are striking and can remain undetected even until late in life.     

Diagnosis of 5alpha-reductase type 2 deficiency: contribution of anti-Müllerian hormone evaluation

AIM: To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5alpha-reductase 2 deficiency. PATIENTS AND METHODS: Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. RESULTS: Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. CONCLUSIONS: Prepubertal patients with 5alpha-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells.     

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.     

Etiology,clinical profile,gender identity and long-term follow up of patients with ambiguous genitalia in India

There is little information on the profile of children with ambiguous genitalia in India. Presented here is an analysis of patients with ambiguous genitalia registered in a general endocrine clinic during the last 2 decades. Seventy-four patients (age 4 months to 36 years) were registered during this period. Fifty-two were more than 5 years old at the time of registration. Thirty-five were reared as females, 29 as males; nine children (4 months to 1 year old) were brought for sex assignment, and one (with epispadias) was brought for correction of urinary incontinence. Investigations revealed 28 patients with congenital adrenal hyperplasia, 14 dysgenetic male pseudohermaphroditism, ten true hermaphroditism, six partial androgen insensitivity, four castration and one epispadias. There were eight patients with perineal hypospadias with normal Leydig cell reserve (normal LH, FSH and testosterone response to LHRH). Sex of rearing and gender identity were concordant in all except the patients with perineal hypospadias with normal Leydig cell response. These observations support the theory that prenatal androgen exposure masculinizes the brain.     

46,XX maleness and 46,XX 21-hydroxylase deficiency in dizygotic twins: association or coincidence?

46,XX maleness is a rare abnormality of gonadal differentiation. We present dizygotic twins, one having ambiguous genitalia due to 2-hydroxylase deficiency, and the other having normal male genitalia with 46,XX maleness. One of the twins was referred to the endocrinology unit at 2 days old because of ambiguous genitalia. The other twin with bilateral undescended testes located in the inguinal canal was diagnosed with 46,XX maleness. The karyotype was 46,XX. Molecular analysis revealed the presence of SRY in the latter twin without Müllerian structures. Association of congenital adrenal hyperplasia (46,XX 21-hydroxylase deficiency) and 46,XX maleness in twins has not been previously reported.     

Familial male pseudohermaphroditism

Familial male pseudohermaphroditism (MPH) due to 17, 20-desmolase deficiency is rare. Here we present two siblings with MPH possibly due to 17, 20-desmolase deficiency. The first patient presented with unambiguous female external genitalia and hypergonadotrophic hypogonadism. Chromosomal analysis revealed 46 XY. Ultrasound evaluation of pelvis revealed gonads in the inguinal canal, and no uterus. These findings were confirmed on laparotomy. Histology revealed the gonads to be testes. The second patient had ambiguous genitalia (perineoscrotal hypospadias, bifid scrotum with palpable gonads) with a 46 XY chromosomal pattern. Both patients had high plasma 17-hydroxy progestrone (17 OHP), low normal dehydro epiandrosterone sulphate (DHEAS) and low plasma testosterone. Plasma testosterone and DHEAS showed no response to ACTH or HCG. These features are compatible with the diagnosis of 17, 20-desmolase deficiency.     

A familial WT1 mutation associated with incomplete Denys–Drash syndrome

Denys–Drash syndrome (DDS) is a rare disorder characterized by nephropathy, male pseudohermaphroditism, and wilms tumor. Cases are thought to arise sporadically through a de novo mutation in the wilms tumor suppressor gene (WT1), which encodes a zinc finger protein that not only acts as a tumor suppressor but is essential for normal gonadogenesis, nephrogenesis, and development of the urogenital tract. In this report, we describe a family with the well-known missense mutation in exon 9 of the WT1 gene, 1180C>T (R394W), causing incomplete DDS and no symptoms in their father. The proband, a boy with 46, XY karyotype, was born with ambiguous genitalia, penoscrotal hypospadias, and bilateral inguinal hernias. At 2 years of age, he has proteinuria and diffuse mesangial sclerosis, but no wilms tumor has been detected. The elder sister of the proband, at 3 years of age, has normal genitalia, proteinuria, focal mesangial sclerosis but no wilms tumor. The WT1 mutation was detected in both patients, who have suspected DDS, and their father, who is phenotypically normal. Conclusion: This case is unusual in that the 1180C>T mutation, which has been found in approximately 50 % of patients with complete DDS, has been inherited and is causing mild or no symptoms of DDS.     

Etiology and clinical profile of ambiguous genitalia an overview of 10 years experience

One hundred nine patients presenting with ambiguous genitalia over the past 10 years (year 1995 to 2004) to Pediatric Endocrine Service of our hospital were reviewed. On the basis of clinical and investigative evaluation like hormonal and biochemical estimations, imaging studies, karyotype and invasive techniques like genitoscopy, laproscopy, open exploration and biopsy of gonads when indicated, these cases could be categorised as Genetic females with virilisation or FPH (n = 30 cases, 27.5 % Genetic males undervirilised or MPH (n = 57 cases, 52.3 %), Disorders of gonadal differentiation (n = 11, 10.1 %) Nine patients with gonadal dysgenesis and 2 with true hermaphroditism and the syndromic form of ambiguous genitalia (n = 2, 1.8 %). Congenital adrenal hyperplasia (CAH) was the underlying cause in all cases of FPH, the salt wasting form in 23/30 and simple virilising form in 7. Major categories in MPH group were Androgen insensitivity syndrome in 28 % (16/57) and 5a reductase deficiency in 23% (13/57).     

SRY基因检测在儿童性发育疾病诊断中的应用

目的：应用SRY基因直接测序检测技术和外周血染色体核型分析技术对外生殖器模糊的幼儿及青春期儿童进行检查以明确诊断。方法：采用常规G显带方法分析20例外生殖器模糊的患儿染色体核型,用PCR技术扩增其SRY基因,进行基因测序,分析是否存在SRY基因及SRY基因是否存在突变情况。结果：20例患儿中SRY基因阳性的有17例,阴性3例。直接测序结果显示所有SRY基因阳性患者该基因均未发生突变。染色体核型分析中检出4例特殊核型为：46, XY, del (Y) (q12)/45, X、46, XY, add (Y) (p11)、46, XY, r (9)及46, XY, 9 qh+。结论：SRY基因检测有助于明确儿童性发育疾病的分型,具有快速检测的优越性,与常规G显带相结合分析有助于儿童性发育疾病的初步诊断。     

True hermaphroditism: 10 years' experience

True hermaphroditism (TH) is the rarest variant of intersex malformations. By definition, these patients have both ovarian and testicular tissue. Most present due to ambiguous genitalia and/or gynecomastia. From 1986 to 1996, we treated 97 patients with intersex disorders; there were 4 with TH. In all cases testicular and ovarian tissue was separate. In 3 patients the external genitalia were ambiguous and 1 had hypoplastic male genitalia. Three patients had a 46, XY and 1 a 46, XX karyotype. Three patients had been listed as males and 1 as a female. The number of operations required varied from 3 to 9 (mean 5.7 per patient). Two patients who had been raised as males finished puberty with hypogenitalism and hypoplastic testes. One married and could have erections, but no ejaculation. Two male patients have been on supplementary androgen therapy. The only patient who had been raised as a female after clitorovaginoplasty had a 6-cm-deep, blind-ending vagina that was deepened to 12 cm with bougienage, so that she was capable of having normal intercourse. It is felt at present that most patients with TH should be raised as females. This was confirmed in our patients as well, which underlines the significance of early diagnosis. Accepted: 11 January 2000     

Features of Antley-Bixler syndrome in an infant born to a mother with pregnancy luteoma

We report a female newborn with characteristic signs of Antley-Bixler syndrome (ABS) such as midface hypoplasia, radiohumeral synostosis and multiple joint contractures. The newborn also presented ambiguous genitalia, stage Prader V, and congenital adrenal hyperplasia. The mother experienced midterm virilization due to a pregnancy luteoma. Her elevated androgen levels and virilization symptoms normalized post partum without treatment. The newborn had elevated serum testosterone and 17-OH-progesterone levels which remained elevated because of a 21-hydroxylase deficiency. The child's treatment in order of priority was: hydrocortisone substitution, craniofacial/skeletal anomaly management and surgical correction of the external genitalia. Mutations in the genes for fibroblast growth factor (FGF) 8 and receptors FGFR1, FGFR2, and FGFR3 were not detected. Conclusion A newborn girl with manifestations of the Antley-Bixler syndrome showed severe virilization probably caused by the association of a mild 21-hydroxylase deficiency and maternal hyperandrogenism due to a pregnancy luteoma. Abnormalities of androgen metabolism may be responsible for virilization reported in other cases of the Antley-Bixler syndrome. Received: 14 May 1999 / Accepted: 3 August 1999