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.     

Clinical, hormonal and cytogenetic evaluation of 46,XX males and review of the literature

The main factor influencing the sex determination of an embryo is the genetic sex determined by the presence or absence of the Y chromosome. However, some individuals carry a Y chromosome but are phenotypically female (46,XY females) or have a female karyotype but are phenotypically male (46,XX males). 46,XX maleness is a rare sex reversal syndrome affecting 1 in 20,000 newborn males. Molecular analysis of sex-reversed patients led to the discovery of the SRY gene (sex-determining region on Y). The presence of SRY causes the bipotential gonad to develop into a testis. The majority of 46, SRY-positive XX males have normal genitalia; in contrast SRY-negative XX males usually have genital ambiguity. A small number of SRY-positive XX males also present with ambiguous genitalia. Phenotypic variability observed in 46,XX sex reversed patients cannot be explained only by the presence or absence of SRY despite the fact that SRY is considered to be the major regulatory factor for testis determination. There must be some other genes either in the Y or other autosomal chromosomes involved in the definition of phenotype. In this article, we evaluate four patients with 46,XX male syndrome with various phenotypes. Two of these cases are among the first reported to be diagnosed prenatally.     

The Silver-Russel syndrome: a case with sexual ambiguity, and a review of literature.

A 38-month-old patient with Silver-Russel syndrome (SRS) and ambiguous genitalia had a 46,XY karyotype on leukocyte and fibroblast cultures. This is the third SRS child with ambiguous genitalia described in the literature. In a review of the findings in 148 reported cases of the syndrome, abnormalities occurring in over 50% of the cases are short stature, craniofacial dysproportion, low birth weight, term gestation, body asymmetry, incurved fifth digits, normal intelligence, short fifth digits, and down-curved corners of the mouth (shark mouth).     

An unusal case of hermaphroditism--a 46,XX/69,XXY chimera

A diploid/triploid karyotype is an uncommon but important cause of true hermaphroditism and ambiguous genitalia. Individuals have a recognisable phenotype and characteristic hydatidiform placental changes. We report a 46,XX/69,XXY chimeric hermaphrodite. This case highlights the typical features (large placenta, intrauterine growth retardation, asymmetric growth, cranio-facial anomalies, syndactyly and pigmentary dysplasia). It illustrates the importance of obtaining skin and gonadal karyotypes in the case of genital ambiguity, as the venous lymphocytic karyotype is usually diploid.     

Disorders of gonadal development: a broad clinical, cytogenetic and histopathologic spectrum

The most complicated group of sexual differentiation disorders is that of gonadal development. Disorders of gonadal development form a wide clinical, cytogenetic and histopathological spectrum. There are still some unsolved difficulties of diagnosis, development of malignancy and the sex rearing of these patients. We reviewed 23 cases of gonadal developmental disorders among 169 patients with ambiguous genitalia or delayed puberty. Among 169 patients, 87 patients were 46,XY disorders of sex development (DSD), 59 patients were 46,XX DSD without disorders of gonadal development and the remaining 23 patients had disorders of gonadal development. Nine of these 23 patients were diagnosed as 46,XY gonadal dysgenesis, 7 patients had ovotesticular DSD, 5 patients had 45,X/46,XY mixed gonadal dysgenesis. Fourteen patients with disorders of gonadal development had genital ambiguity, 5 patients had a female genital phenotype with a palpable gonad and/or delayed puberty. Four patients had the male genital phenotype. Disorder of gonadal development is a very important clinical problem with different aspects of diagnosis, treatment, rearing sex and prophylaxis. Each patient should be evaluated individually employing a multidiciplinary approach.     

Management of children with disorders of sex development: 20-year experience in southern Thailand

Background

Disorders of sex development (DSD) is a group of sexual differentiation disorders resulting in genital anomalies with defects in gonadal hormone synthesis and/or incomplete genital development. These conditions result in problems concerning the sex assignment of the child. This study aims to describe the clinical features, diagnosis and management of children with DSD in southern Thailand.

Methods

The medical records of 117 pediatric patients diagnosed with DSD during the period of 1991–2011 were retrospectively reviewed.

Results

Disorders of sex development were categorized into 3 groups: sex chromosome abnormalities (53.0%), 46,XX DSD (29.9%) and 46,XY DSD (17.1%). The two most common etiologies of DSD were Turner syndrome (36.8%) and congenital adrenal hyperplasia (29.9%). Ambiguous genitalia/intersex was the main problem in 46,XX DSD (94%) and 46,XY DSD (100%). Sex reassignment was done in 5 children (4.3%) at age of 3–5 years: from male to female in 4 children (1 patient with congenital adrenal hyperplasia, 1 patient with 45,X/46,XY DSD, and 2 patients with 46,XX ovotesticular DSD) and from female to male in 1 patient with 46,XX ovotesticular DSD. Of the total 20 children with 46,XY DSD, 16 (80%) were raised as females.

Conclusion

Management of DSD children has many aspects of concern. Sex assignment/reassignment depends on the phenotype (phallus size) of the external genitalia rather than the sex chromosome.     

A Case Series of Five Sri Lankan Patients with Ovotesticular Disorder of Sex Development

Ovotesticular disorder of sex development (OT-DSD) is a rare disorder of sexual differentiation in which the gonads of an individual are characterized by the presence of both mature ovarian and testicular tissues. The objective of this paper is to report the clinical, cytogenetic and histopathological findings in Sri Lankan patients diagnosed with OT-DSD who were referred to the Human Genetics Unit for cytogenetic evaluation during 2005 to 2011. Five patients had histopathologically confirmed OT-DSD. Their ages at presentation ranged from 2 mo to 47 yr. Clinical symptoms varied from ambiguous genitalia and inguinal hernias at birth to a lower abdominal mass presenting in adulthood. All 5 were reared as phenotypic males. An ovotestis was detected in all cases except one, and the predominant karyotype was 46,XY. The findings in this series of predominantly 46,XY karyotype are in contrast to previously published reports that have reported 46,XX as being the predominant karyotype. It is therefore recommended that individuals with ambiguous genitalia who have the 46,XY karyotype should be thoroughly investigated by ultrasonographic or laparoscopic assessment to determine the exact nature of their internal genital organs. OT-DSD should also be considered in the differential diagnosis of patients with cryptorchidism and inguinal hernia.     

WT1 gene mutations in three girls with nephrotic syndrome

Denys-Drash syndrome and Frasier syndrome are two related conditions caused by mutations of the Wilms tumor gene, WT1. Both syndromes are characterized by male pseudohermaphrodism, a progressive glomerulopathy, and the development of genitourinary tumors. This study examines three girls with steroid-resistant nephrotic syndrome related to mutations in the WT1 gene, but with normal 46, XX karyotype and normal female phenotype. WT1 mutation analysis should be routinely done in females with steroid-resistant nephrotic syndrome.     

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。     

Successful pulmonary artery embolectomy in a patient with a saddle Wilms tumor embolus

Denys-Drash syndrome is a genetic disorder characterized by ambiguous genitalia, cryptorchidism, nephrotic syndrome, and a high predilection for Wilms tumor with intravascular invasion. We report a 5-year-old male with Denys-Drash syndrome who rapidly developed Wilms tumor with vascular invasion, subsequent saddle tumor embolus, and required emergent embolectomy. This case illustrates the rapid emergence of Wilms tumor in a patient with Denys-Drash syndrome and the importance of considering embolectomy over thrombolytic therapy for PE in this population, given a high likelihood of tumor embolus.     

Pseudohermaphroditism, glomerulopathy, and Wilms tumor (Drash syndrome): frequency in end-stage renal failure

The sporadic concurrence of male pseudohermaphroditism and chronic glomerulopathy is associated with an extremely high risk of Wilms tumor. We report our experience with an infant who developed this triad (Drash syndrome) and review the 21 patients described in the literature, to emphasize the importance of early diagnosis and to suggest guidelines for management. The dysgenetic gonads are always intra-abdominal and carry a 20% to 30% risk for malignancy. The external genitalia are frequently ambiguous (77%); some children are phenotypically normal females. The glomerulopathy typically leads to end-stage renal failure in infancy; the subsequent death rate has, to date, been 68%. The clinical presentation of renal disease is variable and includes congenital nephrotic syndrome (14%) and infantile nephrotic syndrome (41%); 27% of patients develop proteinuria and renal insufficiency between the ages of 1 and 3 years. The high risk of Wilms tumor (55% in this review) mandates regular tumor surveillance, and prophylactic bilateral nephrectomy and gonadectomy once irreversible renal failure develops.     

The child of uncertain sex: 17 years of experience

OBJECTIVE: To review the common clinical presentations, investigations and final diagnosis of children presenting with genital ambiguity. METHODOLOGY: Retrospective search of the Royal Children's Hospital, Brisbane, Australia, medical records and personal medical database of one of the authors (MJT) between 1982 and 1999. RESULTS: Fifty-one children aged 0.1-14 (mean 3.9) years were identified. Twenty-two cases had a 46XX karyotype, and commonly presented with an enlarged phallus (77.2%), urogenital sinus (63.6%) and labioscrotal fold(s) (40.9%). Congenital adrenal hyperplasia (CAH) was the most common final diagnosis (72.7%). Twenty-nine cases of genital ambiguity had a 46XY karyotype and commonly presented with palpable gonad(s) (75.8%), undescended testes (51.7%), penoscrotal hypospadias (51.7%) and a small phallus (41.3%). Androgen insensitivity and gonadal dysgenesis were the commonest final diagnosis both occurring at a frequency of 17.2%. CONCLUSIONS: The results emphasize the importance of CAH as the most common diagnosis in 46XX cases presenting with ambiguous genitalia. Those with 46XY had a wider range of diagnoses. Despite thorough investigation, 23.5% had no definite final diagnosis made.     

True hermaphroditism: clinical features, genetic variants and gonadal histology

True hermaphroditism is a rare cause of intersexuality in which both ovarian and testicular tissue is present in the same individual. We present the clinical findings, karyotype, gonadal histology and management of eight patients with true hermaphroditism. Their ages ranged from 43 days to 12 years at the first evaluation. The presenting symptoms were ambiguous genitalia (6 patients), isolated clitoromegaly (1 patient) and hypospadias (1 patient). The most common karyotype was 46,XX (6 patients). In one patient the karyotype was 46,XY and in another 45,XO/46,XY mosaicism, which is rare in the literature. A vagina was found by genitography in all patients, and at laparotomy the uterus was found normal in five patients, hypoplastic in one patient, as a fibrous band in one, and absent in the remaining patient. Histological investigation of the gonads revealed bilateral ovotestis in two patients, ovotestis plus ovary in two patients, and ovary on one side and testis on the other side in three patients. Five patients were assigned to the female sex, and three to the male sex. One of these patients was changed from male to female after evaluation.     

Robinow syndrome in two siblings from consanguineous parents

A Kurdish family had two children affected with Robinow syndrome. The daughter had short stature, macrocephaly, hypertelorism, hepatosplenomegaly, short forearms and marked vertebral anomalies. Her brother had hypertelorism, hypertrophied alveolar ridges, hepatosplenomegaly, short forearms, rib anomaly and ambiguous genitalia. The karyotype of the affected male sibling showed mosaicism for 45X, 46,X,dicY(q11.22), 47,X,dicY(q11.22),dicY(q11.22).     

Mixed gonadal dysgenesis and dysgenetic male pseudohermaphroditism—A critical analysis

A 10 year prospective study of 14 patients with mixed gonadal dysgenesis (MGD) and six patients with dysgenetic male pseudohermaphroditism (DMP) is reported. All of them had internal mullerian structures, along with unilateral or bilateral dysgenetic testes, ambiguous external genitalia. Twelve had been brought up as male, nine of whom had a unilateral descended testis. Eight had been reared as females, as they had bilaterally undescended gonads, and ambiguous genitalia. Clinical examination, retrograde genito-urethrography and cytogenetic studies suggested the diganosis in 16 patients, while four were diagnosed on inguino-abdominal exploration for undescended testis. This report delineates more clearly the clinical profile of these orders. All the patients reared as male were assigned the male gender following abdominal gonadectomy, retention of scrotal testis and male genitoplasty. The eight patients who were reared as females underwent bilateral salpingo-gonadectomy and female genitoplasty. This management differs from the usual recommendation that all such children should be reared as females. Ten patients (50%) had maternal history of previous abortion/stillbirth, or drug intake in the first trimester of pregnancy suggesting a role of these factors in the etiology. All cases of DMP had a 46, XY karyotype, while eight of 14 cases of MGD had mosaicism with 45X/46,XY cell lines in blood or gonadal cultures. The clinicopathological features of patients of MGD and DMP were similar. It is suggested that these two disorders represent different spectra of the same disorder. A unifying concept of etiopathogenesis is proposed. This article is based on the presentation in the “International Workshop on Recent Advances in Neonatal Surgery and Intersex Disorders” held at All India Institute of Medical Sciences, New Delhi from March 1–4, 1989.     

Association of partial gonadal dysgenesis, nephropathy and WT1 gene mutation without Wilms' tumor: incomplete Denys-Drash syndrome

The concurrence of ambiguous genitalia, nephropathy and predisposition to Wilms' tumor are characteristics of Denys-Drash syndrome. Some of the reported patients do not express the full spectrum of the syndrome, while the occurrence of nephropathy has become a generally accepted common feature of this syndrome. We report an infant with male pseudohermaphroditism due to partial gonadal dysgenesis and nephropathy without Wilms' tumor but with a Wilms' tumor suppressor gene (WT1) mutation. The high risk of Wilms' tumor mandates regular surveillance and the use of prophylactic bilateral nephrectomy as a treatment is not yet clear.     

Germ cell tumor showing partial trisomy 1 in a gonadectomized intersex child with monosomy X and double Y mosaicism

High incidence of germ cell tumors arising from dysgenetic gonads in patients with sexual chromosome abnormalities has been described, especially in patients with a Y chromosome bearing cell line. Here we report a 14-year-old patient with ambiguous genitalia. Constitutional karyotype showed 45,X/46,X,derY [?t(Yp;Yq)] mosaicism. The patient developed an abdominally located mixed malignant germ cell tumor 5 years after the removal of the dysgenetic gonads. Tumor karyotype showed partial trisomy 1q, a derivative 8q, and a hyperdiploidy with +X, +7, +12, +15, +19, +21, and an unidentified marker.     

21-Hydroxylase deficiency: clinical features, laboratory profile and pointers to diagnosis in Indian children

We evaluated clinical features, laboratory profile and pointers to diagnosis of 21-hydroxylase deficiency in children presenting to the Pediatric Endocrine Clinic of our hospital from 1990 to 2002. Of the 94 patients included in the study 46 had salt wasting form (SW, 21 girls), 44 simple virilizing form (SV, 34 girls) and 4 non-classical form of the disease (NC, all girls). No difference was observed in the mean (95% confidence interval) age at diagnosis in boys and girls with salt wasting (2.3 mo (0.7-3.9 mo) against 1.3 mo (0.9-1.7 mo), p not significant) despite the presence of genital ambiguity in all girls at birth. Diagnosis of salt wasting was missed at admission in 18 boys (72%) and 3 girls (14.3%) highlighting the need for high index of suspicion for the disorder. Eight patients with 46 XX karyotype (14.5%) had male-like external genitalia with cryptorchidism emphasizing the need for evaluation of boys with cryptorchidism for female pseudohermaphroditism. Our study reiterates the need for early recognition and management of 21-hydroxylase deficiency in children in countries where neonatal screening programs are not feasible.     

Carcinoma in situ of the testis in children with 45,X/46,XY gonadal dysgenesis

The frequency of gonadal tumors in intersex patients with a karyotype including a Y chromosome is very high. In other at-risk groups, testicular germ cell tumors have been shown to be preceded by carcinoma in situ (CIS) changes. We investigated gonadal tissue from four children, aged 1 month to 18 years, with 45,X/46,XY gonadal dysgenesis, and with male or ambiguous genitalia, for the presence of CIS germ cells. Twelve gonadal biopsies and gonadectomy specimens were analyzed by means of conventional histology and densitometric DNA measurements. CIS changes were detected in specimens from all four patients, and aneuploid DNA distributions of the CIS germ cells confirmed the malignant potential of these cells. In one case, electron microscopic analysis revealed the same ultrastructural features of the CIS germ cells as previously described in seminoma cells. These observations indicate that in all patients with 45,X/46XY gonadal dysgenesis and a male phenotype, gonadal biopsies should be considered as soon as the syndrome is diagnosed. We believe that the finding of CIS warrants gonadectomy.     

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