👤 Afia Sultana

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetic hereditary cardiomyopathy characterized by sudden cardiac death. Mutations in the MYBPC3 gene are often the most prevalent genetic abnormality in HCM with a prevalence ranging from 20.0 to 42.0%. The mutation spectrum is available for different countries, but such studies are lacking in the Asian population including Bangladeshi patients. A cross-sectional descriptive study was conducted for mutation analysis of the whole MYBPC3 gene on a cohort of 75 HCM Bengali Bangladeshi probands through Next Generation Sequencing at the Genetic Research Lab of Bangabandhu Sheikh Mujib Medical University from 2016 to 2019. The structural and functional impact of the mutations was further analyzed by in silico process. We analyzed the data and found 103 variants in 102 locations in the MYBPC3 gene. Variants were identified in both the coding region and the non-coding region. We found one possibly novel variant in the MYBPC3 gene. The findings of this research will help to develop a genetic database of HCM which will help in the early diagnosis and proper management of HCM patients in Bangladesh. One pathogenic splice donor variant (47356592 C >T) was found in the intronic region. Among the variants in the coding region, one missense mutation was pathogenic (NP₋000247.2: p.Asp770Asn) which was found in seven patients and another one is of conflicting interpretations of pathogenicity (NP₋000247.2: p.Ser217Gly) which was found in two patients. We have identified one in-frame deletion (NP₋000247.2: p.Ala433del) that is possible a novel variant responsible for the development of HCM. Show less

The studies investigating gene-gene and gene-environment (or gene-behavior) interactions provide valuable insight into the pathomechanisms underlying obese phenotypes. The Pakistani population due to its unique characteristics offers numerous advantages for conducting such studies. In this view, the current study was undertaken to examine the effects of gene-gene and gene-environment/behavior interactions on the risk of obesity in a sample of Pakistani population. A total of 578 adult participants including 290 overweight/obese cases and 288 normal-weight controls were involved. The five key obesity-associated genetic variants namely MC4R rs17782313, BDNF rs6265, FTO rs1421085, TMEM18 rs7561317, and NEGR1 rs2815752 were genotyped using the TaqMan allelic discrimination assays. The data related to behavioral factors, such as eating pattern, diet consciousness, the tendency toward fat-dense food (TFDF), sleep duration, sleep-wake cycle (SWC), shift work (SW), and physical activity levels were collected via a questionnaire. Gene-gene and gene-behavior interactions were analyzed by multifactor dimensionality reduction and linear regression, respectively. In our study, only TMEM18 rs7561317 was found to be significantly associated with anthropometric traits with no significant effect of gene-gene interactions were observed on obesity-related phenotypes. However, the genetic variants were found to interact with the behavioral factors to significantly influence various obesity-related anthropometric traits including BMI, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio, and percentage of body fat. In conclusion, the interaction between genetic architecture and behavior/environment determines the outcome of obesity-related anthropometric phenotypes. Thus, gene-environment/behavior interaction studies should be promoted to explore the risk of complex and multifactorial disorders, such as obesity. Show less

The current case-control study sought the association of BDNF rs6265 and MC4R rs17782313 with metabolic syndrome (MetS), MetS components and other related metabolic parameters in a sample of Pakistani subjects. Fasting high-density lipoprotein cholesterol (HDL-C) and homeostatic model assessment of insulin sensitivity showed a significantly lower mean whereas body mass index (BMI), waist circumference, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose, insulin, total cholesterol (TC), low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, triglycerides (TG), cholesterol to HDL-C ratio, TG to HDL-C ratio, homeostatic model assessment of insulin resistance, visceral adiposity index, lipid accumulation product and the product of TG and glucose showed a significantly higher mean in the presence of MetS. Reduced HDL-C appeared as the most frequent and hypertriglyceridemia as the least frequent component of MetS whereas clustering of reduced HDL-C + abdominal obesity (AO) + hyperglycemia appeared as the most prevalent combination of MetS components. Moreover, BDNF rs6265 showed BMI and gender independent association with increased risk of MetS in Pakistani individuals whereas MC4R rs17782313 showed BMI and gender dependent association with increased risk of MetS in Pakistani females. In addition, BDNF rs6265 and MC4R rs17782313 showed gender-dependent associations with decreased risk of having low HDL-C in males and increased risk of having abdominal obesity in females, respectively. However, no association was observed for metabolic variables other than components of MetS across genotypes of both BDNF rs6265 and MC4R rs17782313. Show less

In this study, we report the experience of the only reference clinical next-generation sequencing lab in Saudi Arabia with the first 1000 families who span a wide-range of suspected Mendelian phenotypes. A total of 1019 tests were performed in the period of March 2016-December 2016 comprising 972 solo (index only), 14 duo (parents or affected siblings only), and 33 trio (index and parents). Multigene panels accounted for 672 tests, while whole exome sequencing (WES) represented the remaining 347 tests. Pathogenic or likely pathogenic variants that explain the clinical indications were identified in 34% (27% in panels and 43% in exomes), spanning 279 genes and including 165 novel variants. While recessive mutations dominated the landscape of solved cases (71% of mutations, and 97% of which are homozygous), a substantial minority (27%) were solved on the basis of dominant mutations. The highly consanguineous nature of the study population also facilitated homozygosity for many private mutations (only 32.5% of the recessive mutations are founder), as well as the first instances of recessive inheritance of previously assumed strictly dominant disorders (involving ITPR1, VAMP1, MCTP2, and TBP). Surprisingly, however, dual molecular diagnosis was only observed in 1.5% of cases. Finally, we have encountered candidate variants in 75 genes (ABHD6, ACY3, ADGRB2, ADGRG7, AGTPBP1, AHNAK2, AKAP6, ASB3, ATXN1L, C17orf62, CABP1, CCDC186, CCP110, CLSTN2, CNTN3, CNTN5, CTNNA2, CWC22, DMAP1, DMKN, DMXL1, DSCAM, DVL2, ECI1, EP400, EPB41L5, FBXL22, GAP43, GEMIN7, GIT1, GRIK4, GRSF1, GTRP1, HID1, IFNL1, KCNC4, LRRC52, MAP7D3, MCTP2, MED26, MPP7, MRPS35, MTDH, MTMR9, NECAP2, NPAT, NRAP, PAX7, PCNX, PLCH2, PLEKHF1, PTPN12, QKI, RILPL2, RIMKLA, RIMS2, RNF213, ROBO1, SEC16A, SIAH1, SIRT2, SLAIN2, SLC22A20, SMDT1, SRRT, SSTR1, ST20, SYT9, TSPAN6, UBR4, VAMP4, VPS36, WDR59, WDYHV1, and WHSC1) not previously linked to human phenotypes and these are presented to accelerate post-publication matchmaking. Two of these genes were independently mutated in more than one family with similar phenotypes, which substantiates their link to human disease (AKAP6 in intellectual disability and UBR4 in early dementia). If the novel candidate disease genes in this cohort are independently confirmed, the yield of WES will have increased to 83%, which suggests that most "negative" clinical exome tests are unsolved due to interpretation rather than technical limitations. Show less

Olfm1, a secreted highly conserved glycoprotein, is detected in peripheral and central nervous tissues and participates in neural progenitor maintenance, cell death in brain, and optic nerve arborization. In this study, we identified Olfm1 as a molecule promoting axon growth through interaction with the Nogo A receptor (NgR1) complex. Olfm1 is coexpressed with NgR1 in dorsal root ganglia and retinal ganglion cells in embryonic and postnatal mice. Olfm1 specifically binds to NgR1, as judged by alkaline phosphatase assay and coimmunoprecipitation. The addition of Olfm1 inhibited the growth cone collapse of dorsal root ganglia neurons induced by myelin-associated inhibitors, indicating that Olfm1 attenuates the NgR1 receptor functions. Olfm1 caused the inhibition of NgR1 signaling by interfering with interaction between NgR1 and its coreceptors p75NTR or LINGO-1. In zebrafish, inhibition of optic nerve extension by olfm1 morpholino oligonucleotides was partially rescued by dominant negative ngr1 or lingo-1. These data introduce Olfm1 as a novel NgR1 ligand that may modulate the functions of the NgR1 complex in axonal growth. Show less