[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.

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.