Identification and Computational Analysis of Rare Variants of Known Hearing Loss Genes Present in Five Deaf Members of a Pakistani Kindred.

Hearing loss (HL) is the most common neurosensory defect in humans that affects the normal communication. Disease is clinically and genetically heterogeneous, rendering challenges for the molecular diagnosis of affected subjects. This study highlights the phenotypic and genetic complexity of inherited HL in a large consanguineous Pakistan kindred. Audiological evaluation of all affected individuals revealed varying degree of mild to profound sensorineural HL. Whole exome (WES) of four family members followed by Sanger sequencing revealed candidate disease-associated variants in five known deafness genes: GJB2 (c.231G>A; p.(Trp77 *)), SLC26A4 (c.1337A>G; p.(Gln446Arg)), CDH23 (c.2789C>T; p.(Pro930Leu)), KCNQ4 (c.1672G>A; p.(Val558Met)) and MPDZ (c.4124T>C; p.(Val1375Ala)). All identified variants replaced evolutionary conserved residues, were either absent or had low frequencies in the control databases. Our in silico and 3-Dimensional (3D) protein topology analyses support the damaging impact of identified variants on the encoded proteins. However, except for the previously established "pathogenic" and "likely pathogenic" categories for the c.231G>A (p.(Trp77 *)) allele of GJB2 and c.1377A>G (p.(Gln446Arg)) of SLC26A4, respectively, all the remaining identified variants were classified as "uncertain significance" based on the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) variant pathogenicity guidelines. Our study highlights the complexity of genetic traits in consanguineous families, and the need of combining the functional studies even with the comprehensive profiling of multiple family members to improve the genetic diagnosis in complex inbred families.

Initial assessment of a child with suspected disorder of sex development.

Disorders of sex development (DSD) are defined as discrepancy between chromosomal, gonadal and anatomic sex. The basic principles for the management of DSD include a multidisciplinary approach for gender assignment. Clinical assessment includes a detailed history and examination of external genitalia. Most of the disorders with symmetrical gonades indicate hormonal cause while asymmetrical gonades are found in chromosomal DSDs. Karyotyping will indicate a 46XX DSD, 46 XY DSD or mosicism. Internal anatomy is defined by ultrasonography, genitoscopy and laparoscopy. Human chorionic gonadotrophins (hCG) stimulation test is carried out in under-virilised males to see the function of Leydig cells in testes. The Most common cause of 46XX DSD is congenital adrenal hyperplasia (CAH). The decision of gender assignment surgery is to be taken in a multidisciplinary environment and with informed consent of the parents. Most of 46 XX CAH patients, even if markedly virilised, and 46 XY complete androgen insensitivity syndrome are raised as females. Similarly, most of 5-α reductase deficiency and 17-ß hydroxysteroid dehydrogenase deficiency patients are assigned to the male gender. The decision in cases of mixed gondal dysgenesis and ovotesticular DSD is based on the development of external and internal genitalia. Patients with androgen biosynthetic defects, partial androgen insensitivity syndrome are usually assigned to the male gender.

insilico Characterization and Homology Modeling of Arabitol Dehydrogenase (ArDH) from Candida albican.

BACKGROUND: Arabitol dehydrogenase (ArDH) is involved in the production of different sugar alcohols like arabitol, sorbitol, mannitol, erythritol and xylitol by using five carbon sugars as substrate. Arabinose, d-ribose, d-ribulose, xylose and d-xylulose are known substrate of this enzyme. ArDH is mainly produced by osmophilic fungi for the conversion of ribulose to arabitol under stress conditions. Recently this enzyme has been used by various industries for the production of pharmaceutically important sugar alcohols form cheap source than glucose. But the information at structure level as well as its binding energy analysis with different substrates was missing. RESULTS: The present study was focused on sequence analysis, insilico characterization and substrate binding analysis of ArDH from a fungus specie candida albican. Sequence analysis and physicochemical properties showed that this protein is highly stable, negatively charged and having more hydrophilic regions, these properties made this enzyme to bind with number of five carbon sugars as substrate. The predicted 3D model will helpful for further structure based studies. Docking analysis provided free energies of binding of each substrate from a best pose as arabinose -9.8224calK/mol, dribose -11.3701Kcal/mol, d-ribulose -8.9230Kcal/mol, xylose -9.7007Kcal/mol and d-xylulose 9.7802Kcal/mol. CONCLUSION: Our study provided insight information of structure and interactions of ArDH with its substrate. These results obtained from this study clearly indicate that d-ribose is best substrate for ArDH for the production of sugar alcohols. This information will be helpful for better usage of this enzyme for hyper-production of sugar alcohols by different industries.