FGD1-related Aarskog-Scott syndrome: Identification of four novel variations and a literature review of clinical and molecular aspects.

Patients with Aarskog-Scott syndrome (AAS) have short stature, facial anomalies, skeletal deformities, and genitourinary malformations. FYVE, RhoGEF, and PH domain-containing 1 (FGD1) is the only known causative gene of AAS. However, the diagnosis of AAS remains difficult, and specific treatments are still absent. Patients suspected with AAS were recruited, and clinical information was collected. Genetic testing and functional analysis were carried out for the diagnosis. By literature review, we summarized the clinical and genetic characteristics of FGD1-related AAS and analyzed the genotype-phenotype correlation. Five patients were recruited, and four novel FGD1 variants were identified. The diagnosis of AAS was confirmed by genetic analysis and functional study. Three patients treated with growth hormone showed improved heights during the follow-up period. By literature review, clinical features of AAS patients with FGD1 variants were summarized. Regarding FGD1 variations, substitutions were the most common form, and among them, missense variants were the most frequent. Moreover, we found patients with drastic variants showed higher incidences of foot and genitourinary malformations. Missense variants in DH domain were related to a lower incidence of cryptorchidism.   Conclusion: We reported four novel pathogenic FGD1 variations in AAS patients and confirmed the efficacy and safety of growth hormone treatment in FGD1-related AAS patients with growth hormone deficiency. Additionally, our literature review suggested the crucial role of DH domain in FGD1 function. What is Known: • Aarskog-Scott syndrome is a rare genetic disease, and the only known cause is the variant in FGD1 gene. The typical clinical manifestations of AAS include facial, skeletal, and urogenital deformities and short stature. What is New: • We reported four novel FGD1 variants and reported the treatment of growth hormone in FGD1-related AAS patients. Our genotype-phenotype correlation analysis suggested the crucial role of DH domain in FGD1 function.

Characteristic external genitalia in male neonates with 5α-reductase deficiency.

There have been no reports comparing neonatal external genitalia of 5α-reductase deficiency (5αRD) with those of other 46,XY differences of sex differentiation (DSD). This study enrolled 31 Japanese cases of 46,XY DSD whose external genitalia was examined during the neonatal period; four were diagnosed as 5αRD and 15 were defined as non-5αRD by genetic analysis of SRD5A2 or urinary steroid metabolites. We compared the following characteristics between 5αRD and non-5αRD groups, adjusting the severity of undermasculinization of the external genitalia: stretched penile length (SPL), glans width, location of the external urethral opening, and proportion of undescended testis. The external genitalia of all the 5αRD cases were Quigley classification grade 2 or 3. We compared the phenotypes between the four 5αRD cases and 11 non-5αRD cases with grade 2 or 3. The median (range) of SPL in the 5αRD group (14 mm [11-16]) was significantly lower than that in the non-5αRD group (22 mm [15-29]) (p = 0.003). An SPL cut-off value of <15 mm yielded a sensitivity of 50% (95% confidence interval [CI]; 7-93%) and specificity of 100% (95% CI, 72-100%) for discriminating between the groups. The median glans width, location of the external urethral opening, and proportion of undescended testis were not significantly different between the groups. The SPL of 5αRD in Quigley classification grade 2 or 3 was significantly shorter than that of other 46,XY DSDs with the equivalent grade.

Novel truncating variants in FGD1 detected in two Danish families with Aarskog-Scott syndrome and myopathic features.

Aarskog-Scott syndrome (AAS) is a developmental disorder, caused by disease-causing hemizygous variants in the FGD1 gene. AAS is characterized by dysmorphic features, genital malformation, skeletal anomalies, and in some cases, intellectual disability and behavioral difficulties. Myopathy has only been reported once in two affected siblings diagnosed with AAS. Only few adult cases have been reported. This article reports four adults with AAS (three male cases and one female carrier) from two unrelated Danish families, all males presented with variable features suggestive of myopathy. All four carried novel hemizygous pathogenic variants in the FGD1 gene; one family presented with the c.2266dup, p.Cys756Leufs*19 variant while the c.527dup; p.Leu177Thrfs*40 variant was detected in the second family. All males had some mild myopathic symptoms or histological abnormalities. Case 1 had the most severe myopathic phenotype with prominent proximal muscular fatigue and exercise intolerance. In addition, he had multiple deletions of mtDNA and low respiratory chain activity. His younger nephew, case 3, had difficulties doing sports in his youth and had a mildly abnormal muscle biopsy and relatively decreased mitochondrial enzyme activity. The singular case from family 2 (case 4), had a mildly myopathic muscle biopsy, but no overt myopathic symptoms. Our findings suggest that myopathic involvement should be considered in AAS.

Ontogeny of estrogen receptors in human male and female fetal reproductive tracts.

This paper reviews and provides new observations on the ontogeny of estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) in developing human male and female internal and external genitalia. Included in this study are observations on the human fetal uterine tube, the uterotubal junction, uterus, cervix, vagina, penis and clitoris. We also summarize and report on the ontogeny of estrogen receptors in the human fetal prostate, prostatic urethra and epididymis. The ontogeny of ESR1 and ESR2, which spans from 8 to 21 weeks correlates well with the known "window of susceptibility" (7-15 weeks) for diethylstilbestrol (DES)-induced malformations of the human female reproductive tract as determined through examination of DES daughters exposed in utero to this potent estrogen. Our fairly complete mapping of the ontogeny of ESR1 and ESR2 in developing human male and female internal and external genitalia provides a mechanistic framework for further investigation of the role of estrogen in normal development and of abnormalities elicited by exogenous estrogens.

Aortic root aneurysm in a patient with Aarskog-Scott syndrome.

We present the case of a 69 years old man affected by Aarskog-Scott syndrome. He came to our attention for an aneurysm of the aortic root, with almost moderate aortic regurgitation; moderate mitral regurgitation was discovered during preoperative assessment. We performed a modified Bentall's procedure and mitral valve repair. A patent foramen ovale was closed. Aarskog-Scott syndrome is a complex developmental disorder, characterized by X-linked recessive hereditariness short stature, craniofacial abnormalities, hyperextension of the proximal interphalangeal joints, and genital malformations. Diagnosis is still a challenge, in light of various clinical pictures and features in common with other syndromes (i.e., Noonan, SHORT, and Robinow syndromes). It has been longly debated if cardiac surveillance is needed among the affected patients; it should be probably undertaken, in view of the higher incidence of congenital heart disease. Moreover, the presence of extremely flexible joints suggests the coexistence of a connective tissue disorder.

The Prevalence of Clinical Features in Patients with Aarskog-Scott Syndrome and Assessment of Genotype-Phenotype Correlation: A Systematic Review.

Aarskog-Scott syndrome is a genetically and clinically heterogeneous rare condition caused by a pathogenic variant in the FGD1 gene. A systematic review was carried out to analyse the prevalence of clinical manifestations found in patients, as well as to evaluate the genotype-phenotype correlation. The results obtained show that clinical findings of the craniofacial, orthopaedic, and genitourinary tract correspond to the highest scores of prevalence. The authors reclassified the primary, secondary, and additional criteria based on their prevalence. Furthermore, it was possible to observe, in accordance with previous reports, that the reported phenotypes do not present a direct relation to the underlying genotypes.

A novel truncating variant in the FGD1 gene associated with Aarskog-Scott syndrome in a family previously diagnosed with Tel Hashomer camptodactyly.

Tel Hashomer camptodactyly syndrome is a long-known entity characterized by camptodactyly with muscular hypoplasia, skeletal dysplasia, and abnormal palmar creases. Currently, the genetic basis for this disorder is unknown, thus there is a possibility that this clinical presentation may be contained within another genetic diagnosis. Here, we present a multiplex family with a previous clinical diagnosis of Tel Hashomer camptodactyly syndrome. Whole exome sequencing and pedigree-based analysis revealed a novel hemizygous truncating variant c.269_270dup (p.Phe91Alafs*34) in the FGD1 gene (NM_004463.3) in all three symptomatic patients, congruous with a diagnosis of Aarskog-Scott syndrome. Our report adds to the limited data on Aarskog-Scott syndrome, and emphasizes the importance of unbiased comprehensive molecular testing toward establishing a diagnosis for genetic syndromes with unknown genetic basis.

[Analysis of FGD1 gene variant in a child with Aarskog-Scott syndrome].

OBJECTIVE: To detect pathogenic variant of the FGD1 gene in a boy with Aarskog-Scott syndrome. METHODS: Genetic variant was detected by high-throughput sequencing. Suspected variant was verified by Sanger sequencing. The nature and impact of the candidate variant were predicted by bioinformatic analysis. RESULTS: The child was found to harbor a novel c.1906C>T hemizygous variant of the FGD1 gene, which has led to conversion of Arginine to Tryptophane at codon 636(p.Arg636Trp). The same variant was found in his mother but not father. Based on the American College of Medical Genetics and Genomics guidelines, the c.1906C>T variant of FGD1 gene was predicted to be likely pathogenic(PM1+PM2+PM5+PP2+PP3+PP4). CONCLUSION: The novel c.1906C>T variant of the FGD1 gene may underlay the Aarskog-Scott syndrome in this child. Above finding has enabled diagnosis for the boy.

Surgical treatment and outcome of complete unilateral urinary tract duplication in a dog.

OBJECTIVE: To report the surgical technique and outcome for correction of complete unilateral duplication of the left urinary tract in a dog. ANIMALS: One 7-month-old entire male Jack Russell terrier. STUDY DESIGN: Case report METHODS: A dog was referred for investigation because of urinary incontinence (UI), preputial irritation (pruritus), diphallia, and cryptorchidism. Computed tomography including urethrographic studies revealed a left duplex kidney, double ectopic left ureters, and a duplex urinary bladder comprising two halves separated by a median septum, each of which emptied into a separate urethra which coursed through separate penises. The left testis was abdominally retained. The right upper urinary tract was considered normal, and the right testis was within the scrotum. Left sided ureteronephrectomy was performed, the median bladder septum was ablated, and the left urethra was ligated. The left penis was partially amputated, and the dog was castrated. RESULTS: Urinary incontinence was improved but persisted after surgery. After repeat imaging, revision surgery was performed 3 months later in which the distal stumps of the (left) ectopic ureters were found to be filling with urine from the right urethra. Urinary incontinence resolved after resection of these ureteric stumps from the prostate and complete transection of the left urethra. CONCLUSION: Extensive surgery with resection and correction of urinary tract duplication was successful in resolving UI in this case. Urogenital duplication should be considered a rare cause of UI. The presence of external congenital deformity (eg, diphallia) should alert clinicians to the possibility of significant concurrent internal abnormalities.

Dental and Maxillofacial Signs in Aarskog Syndrome: A Review of 3 Siblings and the Literature.

PURPOSE: Dagfinn Aarksog first described faciodigitogenital syndrome in 1970. Its inheritance is X linked and autosomally recessive. Currently, the diagnosis of Aarskog-Scott syndrome (ASS) is based on clinical dysmorphologic findings and can be supported by genetic examination. REPORT OF CASES: This report describes 3 brothers already diagnosed with ASS who were referred for examination of oral and maxillofacial malformations associated with ASS. They presented classic features of ASS, such as digital and genital (shawl scrotum) anomalies. More specifically, in terms of orbitopalpebral malformations, they showed marked ptosis with hypertelorism and antimongoloid palpebral fissure that gave them the characteristic facies. Concerning their oral and maxillofacial malformations, they had dental and skeletal major discrepancies and some dental agenesia. DISCUSSION AND CONCLUSION: ASS is a rare X-linked syndrome composed of numerous morphologic facial, digital, and genital anomalies. The diagnosis is established genetically with the FGD1 mutation but there is no phenotypic and genotypic correlation with FGD1 mutations. Concerning maxillofacial malformations, maxillary and mandibular hypoplasia with jaw discrepancies can be found, as can teeth anomalies. It seems that these anomalies are widely underestimated.

Maternal Overweight and Obesity and Genital Anomalies in Male Offspring: A Population-Based Swedish Cohort Study.

BACKGROUND: Overweight and obese pregnant women face higher risk of several critical birth outcomes, including an overall increased risk of congenital abnormalities. Only few studies have focused on associations between maternal overweight and the genital anomalies in boys, cryptorchidism and hypospadias, and results are inconclusive. METHODS: We performed a population-based cohort study and assessed the associations between maternal body mass index (BMI) in early pregnancy and occurrence of cryptorchidism and hypospadias. All live-born singleton boys born in Sweden from 1992 to 2012 were included. From the Swedish Patient Register, information on cryptorchidism and hypospadias was available. Data were analysed using Cox proportional hazards regression adjusted for potential confounders. Mediation analyses were performed to estimate how much of the association between BMI and genital anomalies were mediated through obesity-related diseases. RESULTS: Of the 1 055 705 live-born singleton boys born from 1992 to 2012, 6807 (6.4 per 1000) were diagnosed with hypospadias and 16 469 (15.6 per 1000) were diagnosed with cryptorchidism, of which 9768 (9.3 per 1000) underwent corrective surgery for cryptorchidism. We observed dose-response associations between maternal BMI and hypospadias and cryptorchidism. Boys of mothers with BMI ≥40.0 kg/m2 had the highest adjusted hazard ratios for hypospadias (HR 1.35, 95% confidence interval [CI] 1.04, 1.76) and cryptorchidism (HR 1.25, 95% CI 1.00, 1.58). A substantial proportion of the associations between BMI and the genital anomalies were mediated through preeclampsia. CONCLUSION: This large register-based study adds to the current literature and indicates that the occurrence of hypospadias and cryptorchidism increase with maternal overweight and obesity severity.

Extended clinical features associated with novel Glis3 mutation: a case report.

BACKGROUND: Mutations in the GLI-similar 3 (GLIS3) gene encoding the transcription factor GLIS3 are a rare cause of neonatal diabetes and congenital hypothyroidism with 12 reported patients to date. Additional features, previously described, include congenital glaucoma, hepatic fibrosis, polycystic kidneys, developmental delay, facial dysmorphism, osteopenia, sensorineural deafness, choanal atresia, craniosynostosis and pancreatic exocrine insufficiency. CASE PRESENTATION: We report a new case for consanguineous parents with homozygous novel mutation in GLIS3 gene who presented with neonatal diabetes mellitus, severe resistant congenital hypothyroidism, cholestatic liver disease, bilateral congenital glaucoma and facial dysmorphism. There were associated abnormalities in the external genitalia in form of bifid scrotum, bilateral undescended testicles, microphallus and scrotal hypospadias which might be a coincidental finding. CONCLUSIONS: We suggest that infants with neonatal diabetes associated with dysmorphism should be screened for GLIS3 gene mutations.

A novel, putatively null, FGD1 variant leading to Aarskog-Scott syndrome in a family from UAE.

BACKGROUND: The X-linked condition "Aarskog-Scott syndrome (AAS)" causes a characteristic combination of short stature, facial, genital and skeletal anomalies. Studies elucidated a causative link between AAS and mutations in the FGD1 gene, which encodes a Rho/Rac guanine exchange factor. FGD1 is involved in regulating signaling pathways that control cytoskeleton organization and embryogenesis. CASE PRESENTATION: FGD1 was studied in an Emirati family with two cases of AAS using PCR amplification and direct sequencing of the entire coding region of the gene. Various in silico tools were also used to predict the functional consequences of FGD1 mutations. In the reported family, two brothers harbor a novel hemizygous mutation in FGD1 c.53del (p.Pro18Argfs*106) for which the mother is heterozygous. This frameshift deletion, being close to N-terminus of FGD1, is predicted to shift the reading frame in a way that it translates to 105 erroneous amino acids followed by a premature stop codon at position 106. Full molecular and clinical accounts about the variant are given so as to expand molecular and phenotypical knowledge about this disorder. CONCLUSIONS: A novel variant in FGD1 was found in an Emirati family with two brothers suffering from AAS. The variant is predicted to be a null mutation, and this is the first report of its kind from the United Arab Emirates.

How the Child's Gender Matters for Families Having a Child With Congenital Adrenal Hyperplasia.

Children with congenital adrenal hyperplasia (CAH) are exposed to high levels of testosterone in utero often resulting in nontypical genitalia at birth for girls. The purpose of this analysis, which draws on data from a larger study, was to examine, based on the gender of the child, the family experiences of having a child with CAH. Sixteen parents were interviewed, and comparisons were made across all categories coded in the parents' interviews to examine similarities and differences in the experiences of families based on the child's gender. Families having a daughter with CAH experienced additional challenges when compared with families having a son. These include fear of stigmatization, challenging surgical decisions, and concerns regarding disclosure of the condition. Acknowledging this and creating support programs tailored for girls that address surgical procedures and complications resulting from being born with elevated testosterone are critical to promoting a healthy family and child response.

[Regulatory effect of faciogenital dysplasia 6 gene on hepatic stem cell differentiation].

Objective: To investigate the regulatory effect of faciogenital dysplasia 6 (FGD6) gene on hepatic stem cell differentiation. Methods: FGD6 gene was selected for the co-intervention of target sequence, the AdEasy system was used for the construction of adenovirus vector and the packaging and multiplication of the recombinant adenovirus vector pSES-FGD6-siRNA, and the HP14.5 cells were infected. Immunofluorescence assay was used to measure the expression of FGD6 protein in HP14.5 cells, quantitative real-time PCR was used to measure the mRNA expression of FGD6, alpha-fetoprotein (AFP), and albumin (Alb), and Western blot was used to measure the protein expression of FGD6, AFP, and Alb. The empty pSES-Ad-RFP adenovirus vector was constructed as control in each group. All data were expressed as x±s, and a one-way analysis of variance was performed. Results: FGD6 protein was mainly expressed in the nucleus of HP14.5 cells. The pSES-FGD6-siRNA adenovirus vector was successfully constructed and it downregulated the expression of FGD6 gene and the mRNA and protein expression of AFP in HP14.5 cells and upregulated the mRNA and protein expression of Alb (P < 0.01). Conclusion: The inhibition of the expression of FGD6 gene in HP14.5 cells may differentiate HP14.5 cells into hepatocytes. Therefore, FGD6 gene plays an important role in the differentiation regulation of hepatic stem cells.

First trimester phthalate exposure and male newborn genital anomalies.

BACKGROUND: Anti-androgenic phthalates are environmental chemicals that affect male genital development in rodents leading to genitourinary birth defects. We examined whether first trimester phthalate exposure may exert similar effects in humans leading to an increased incidence of newborn male genital anomalies in a multi-center cohort study. METHODS: We recruited first trimester pregnant women within The Infant Development and the Environment Study (TIDES) from 2010 to 2012 from four study centers and limited analyses to all mother/male infant dyads who had complete urinary phthalate and birth exam data (N=371). We used multivariate logistic regression to determine the odds of having a genital anomaly in relation to phthalate exposure. RESULTS: Hydrocele was the primary abnormality observed in the cohort (N=30) followed by undescended testes (N=5) and hypospadias (N=3). We observed a statistically significant 2.5 fold increased risk (95% CI 1.1, 5.9) of having any anomaly and 3.0 fold increased risk (95% CI 1.2, 7.6) of isolated hydrocele in relation to a one log unit increase in the sum of di-ethylhexyl phthalate (DEHP) metabolites. CONCLUSIONS: First trimester urinary DEHP metabolite concentrations were associated with increased odds of any newborn genital anomaly, and this association was primarily driven by isolated hydrocele which made up the majority of anomalies in newborn males. The association with hydrocele has not been previously reported and suggests that it may be an endpoint affected by prenatal phthalate exposures in the first trimester of development. Future human studies should include hydrocele assessment in order to confirm findings.

Prenatal diethylstilbestrol induces malformation of the external genitalia of male and female mice and persistent second-generation developmental abnormalities of the external genitalia in two mouse strains.

Potential trans-generational influence of diethylstilbestrol (DES) exposure emerged with reports of effects in grandchildren of DES-treated pregnant women and of reproductive tract tumors in offspring of mice exposed in utero to DES. Accordingly, we examined the trans-generational influence of DES on development of external genitalia (ExG) and compared effects of in utero DES exposure in CD-1 and C57BL/6 mice injected with oil or DES every other day from gestational days 12 to 18. Mice were examined at birth, and on 5-120 days postnatal to evaluate ExG malformations. Of 23 adult (>60 days) prenatally DES-exposed males, features indicative of urethral meatal hypospadias (see text for definitions) ranged from 18% to 100% in prenatally DES-exposed CD-1 males and 31% to 100% in prenatally DES-exposed C57BL/6 males. Thus, the strains differed only slightly in the incidence of male urethral hypospadias. Ninety-one percent of DES-exposed CD-1 females and 100% of DES-exposed C57BL/6 females had urethral-vaginal fistula. All DES-exposed CD-1 and C57BL/6 females lacked an os clitoris. None of the prenatally oil-treated CD-1 and C57BL/6 male and female mice had ExG malformations. For the second-generation study, 10 adult CD-1 males and females, from oil- and DES-exposed groups, respectively, were paired with untreated CD-1 mice for 30 days, and their offspring evaluated for ExG malformations. None of the F1 DES-treated females were fertile. Nine of 10 prenatally DES-exposed CD-1 males sired offspring with untreated females, producing 55 male and 42 female pups. Of the F2 DES-lineage adult males, 20% had exposed urethral flaps, a criterion of urethral meatal hypospadias. Five of 42 (11.9%) F2 DES lineage females had urethral-vaginal fistula. In contrast, all F2 oil-lineage males and all oil-lineage females were normal. Thus, prenatal DES exposure induces malformations of ExG in both sexes and strains of mice, and certain malformations are transmitted to the second-generation.

Comparative effects of neonatal diethylstilbestrol on external genitalia development in adult males of two mouse strains with differential estrogen sensitivity.

The effect of neonatal exposure to diethylstilbestrol (DES), a potent synthetic estrogen, was examined to evaluate whether the CD-1 (estrogen insensitive, outbred) and C57 (estrogen sensitive, inbred) mouse strains differ in their response to estrogen disruption of male ExG differentiation. CD-1 and C57BL/6 litters were injected with sesame oil or DES (200 ng/g/5 µl in sesame oil vehicle) every other day from birth to day 10. Animals were sacrificed at the following time points: birth, 5, 10 and 60 days postnatal. Neonatally DES-treated mice from both strains had many ExG abnormalities that included the following: (a) severe truncation of the prepuce and glans penis, (b) an abnormal urethral meatus, (c) ventral tethering of the penis, (d) reduced os penis length and glans width, (e) impaired differentiation of cartilage, (f) absence of urethral flaps, and (g) impaired differentiation of erectile bodies. Adverse effects of DES correlated with the expression of estrogen receptors within the affected tissues. While the effects of DES were similar in the more estrogen-sensitive C57BL/6 mice versus the less estrogen-sensitive CD-1 mice, the severity of DES effects was consistently greater in C57BL/6 mice. We suggest that many of the effects of DES, including the induction of hypospadias, are due to impaired growth and tissue fusion events during development.