A novel homozygous FAM92A gene (CIBAR1) variant further confirms its association with non-syndromic postaxial polydactyly type A9 (PAPA9).

Polydactyly is a very common digit anomaly, having extra digits in hands and/or toes. Non-syndromic polydactyly in both autosomal dominant and autosomal recessive forms are caused by disease-causing variants in several genes, including GLI1, GLI3, ZNF141, FAM92A, IQCE, KIAA0825, MIPOL1, STKLD1, PITX1, and DACH1. Whole exome sequencing (WES) followed by bi-directional Sanger sequencing was performed for the single affected individual (II-1) of the family to reveal the disease causative variant/gene. 3D protein modeling and structural molecular docking was performed to determine the effect of the identified mutation on the overall protein structure. WES revealed a novel biallelic missense variant (c.472G>C; p.Ala158Pro) in exon 6 of the FAM92A gene. The identified variant segregated perfectly with the disease phenotype using Sanger sequencing. Furthermore, Insilco analysis revealed that the variant significantly changes the protein secondary structure, and substantially impact the stability of FAM92A. We report the second FAM92A disease-causing mutation associated with recessive non-syndromic postaxial polydactyly. The data further confirms the contribution of FAM92A in limb development and patterning.

Genetic overview of postaxial polydactyly: Updated classification.

Polydactyly or polydactylism, also known as a hyperdactyly, is a congenital limb defect with various morphologic phenotypes. Apart from physical and functional impairments, the presence of polydactyly is an indication of an underlying syndrome in the newborn. Usually, it follows as an autosomal dominant/recessive inheritance pattern with defects in the limb development's anteroposterior patterning. Although mutations in several genes have been associated with polydactyly; however, the exact underlying cause, pathways, and disease mechanisms are still unexplored, thus making it of multi-factorial origin. Polydactyly is divided into three subtypes; radial, ulnar, and central polydactyly. So far, 11 loci (PAPA1-PAPA11) and seven human genes have been reported to cause non-syndromic postaxial polydactyly in humans, including the ZNF141, GLI3, IQCE, GLI1, FAM92A1, KIAA0825, and DACH1. In this review, we discuss emerging evidences of clinical and molecular characterization of polydactyly types in term of the involvement of newly associated genes and loci for non-syndromic postaxial polydactyly, and how these might impact our understanding of the genetic mechanisms and molecular etiology involved in the cause of polydactyly.

Association of leukocyte telomere attrition in coronary artery disease in Pakistani population: A case-control study with meta-analysis.

BACKGROUND: Coronary arteries disease (CAD) is one of the primary causes of mortality worldwide. Genetic, epigenetic and environmental factors have been hypothesized in the pathogenesis of CAD. Leukocyte telomere length (LTL) has been proposed as a potential biomarker for early detection of atherosclerosis. Telomere is the DNA-Protein structure that maintains stability and integrity of chromosomes and is associated with the aging-related cellular mechanisms. This study is designed to investigate the association of LTL with CAD pathogenesis. MATERIAL AND METHOD: This prospective case-control study included 100 patients and 100 control individuals. DNA was extracted from the peripheral blood samples, and LTL was measured using real-time PCR. Data were normalized with single copy gene and presented as relative telomere length T/S ratio. Comprehensive meta-analysis was conducted to ascertain the pivotal role of telomere length in CAD pathology across multiple populations. RESULTS: Our results showed shorter telomere length in CAD patients as compared to control. The correlation analysis revealed a significant (P-value <0.01) negative correlation between telomere length with basal metabolic index (BMI), total cholesterol, and low-density lipoprotein cholesterol (LDL-C) and a positive correlation with high-density lipoprotein cholesterol (HDL-C). Meta-analysis results indicated a significantly shorter telomere length in the Asian population and a non-significant shorter telomere length in other populations. Receiver operator curve (ROC) analysis demonstrated an area under the curve (AUC) of 0.814 with cut-off value of 0.691 exhibited sensitivity of 72.2%, and specificity of 79.1%, for the diagnosis of CAD. CONCLUSION: In conclusion, LTL is associated with the onset of CAD and could be used as a diagnostic predictor to screen individuals with CAD.