Aarskog-Scott syndrome: a novel mutation in the FGD1 gene associated with severe craniofacial dysplasia

Velopharyngeal Characteristics in Aarskog-Scott Syndrome: A Case Report

Aarskog-Scott syndrome (AAS), also known as facio-digito-genital syndrome, is a rare heterogenous syndrome characterized by facial dysmorphism, brachydactyly, and genetic abnormalities. Although severe craniofacial abnormalities have been reported in AAS, little is known about speech and resonance issues in AAS. Specifically, published data to date have only indicated reports of hypernasality associated with a cleft palate in AAS. This case report provides clinical and anatomic information surrounding hypernasal speech in the absence of an overt cleft palate in a patient with AAS.

A novel frameshift mutation in the FGD1 gene causing Aarskog-Scott syndrome patient with hypogonadism: a case report

Aarskog-Scott syndrome (AAS) is most commonly inherited as an X-linked recessive genetic disease caused by FGD1 mutations. AAS patients are most frequently male, and the clinical manifestations of facial abnormalities, skeletal deformities, and abnormal genitalia comprise a characteristic triad of diagnostic features. The results on the clinical and molecular analysis of a family that reveals a novel FGD1 gene frameshift mutation in an 11-year-old boy displaying bilateral cryptorchidism associated with hypogonadism are reported here. This patient exhibited a characteristic triad of diagnostic features of ASS, including short stature, facial abnormalities, joint laxity, and typical scrotal fold. Whole-exome sequencing revealed the novel hemizygous mutation c.500delA in exon 3 of the patient's FGD1 gene, resulting after a frameshift in the Tyr167 residue, while his mother is heterozygous of the same variant. Further in silico studies were performed to identify the pathological consequence of this gene mutation. Thus, our study shows that frameshifts disrupting the RhoGEF gene domain of FGD1 represent the most prevalent causal mutations underlying AAS and expand the phenotypic and mutational spectra of this disease. Improved understanding of the phenotypic and pathological heterogeneity accompanying FGD1 mutation can greatly enhance the clinical prognostic capabilities in the future and aid genetic counseling for AAS patients.

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.

The prognostic value of faciogenital dysplasias as biomarkers in head and neck squamous cell carcinoma

Aim: This present study aims to investigate the prognostic value of FGD genes for predicting the overall survival in head and neck squamous cell carcinoma (HNSC) patients. Materials & methods: Clinical information and FGD gene expressions of 513 HNSC patients were obtained from The Cancer Genome Atlas dataset. Kaplan–Meier survival, Pearson correlation coefficient analyses and enrichment analyses were performed based on The Cancer Genome Atlas dataset, as well as FGD gene expressions analysis in normal tissues. Results: The survival analyses showed that high levels of FGD2 and FGD3 mRNA expressions, and the combination of high levels of FGD2 and FGD3 mRNAs were associated with the favorable overall survival in HNSC patients (p < 0.01). Oppositely, no significant correlations (p > 0.05) were observed between gender and race and OS. Conclusion: Our findings suggest that the expression levels of FGD2 and FGD3 mRNAs in HNSC are associated with favorable prognosis and may be regarded as potential prognostic biomarkers.

Novel variant in the FGD1 gene causing Aarskog-Scott syndrome

Aarskog-Scott syndrome (ASS) is a rare, X-linked recessive inherited disorder. Affected individuals may develop short stature and exhibit distinctive skeletal and genital development. Mutations in the FYVE, rhogef and pleckstrin homology domain-containing protein 1 (FGD1) gene, located within the Xp11.21 region, are responsible for the occurrence of ASS. Since it is rare and complex, it can take a long time to obtain a definitive clinical diagnosis unless clinicians are familiar with the disease. In the present study, whole-exome sequencing (WES) was performed to screen for causal variants in a Chinese pediatric patient who exhibited a number of clinical symptoms of ASS, including short stature, facial abnormalities, stubby metacarpals and swollen testis. DNA sequencing revealed a novel c.1270 A>G mutation in exon 6 of the FGD1 gene, which led to an amino acid conversion of asparagine to aspartic acid on codon 424 and in silico analysis indicated that this novel missense mutation was pathogenic. The present study identified a novel variant of the FGD1 gene and to the best of our knowledge, is the first report of ASS in a Chinese individual. The results indicated that WES is an effective tool for the diagnosis of rare and complex syndromes such as ASS.

Identification of novel mutations in Mexican patients with Aarskog-Scott syndrome

Aarskog-Scott syndrome (AAS), also known as faciogenital dysplasia (FGD, OMIM # 305400), is an X-linked disorder of recessive inheritance, characterized by short stature and facial, skeletal, and urogenital abnormalities. AAS is caused by mutations in the FGD1 gene (Xp11.22), with over 56 different mutations identified to date. We present the clinical and molecular analysis of four unrelated families of Mexican origin with an AAS phenotype, in whom FGD1 sequencing was performed. This analysis identified two stop mutations not previously reported in the literature: p.Gln664* and p.Glu380*. Phenotypically, every male patient met the clinical criteria of the syndrome, whereas discrepancies were found between phenotypes in female patients. Our results identify two novel mutations in FGD1, broadening the spectrum of reported mutations; and provide further delineation of the phenotypic variability previously described in AAS.