Coronavirus disease 2019 (COVID-2019) started in Wuhan, China, in December 2019. Angiotensin-converting enzyme 2 (ACE2) receptor was one of the most important genes related to the entrance of the virus to the host. Until now, several variations have been identified in ACE2 and related transmembrane protease serine 2. Epigenetic modifications not only play an important role during the maintenance of genome and cellular homoeostasis but also for the etiopathophysiology of the virus infection. Studies showed methylation of ACE2 was changed to depend on host and age of the host during the viral infection.
In this study, we provided an epigenetics point of view to the coronavirus infection. We highlight the importance of epigenetic modifications during viral replication and infection and their interaction with COVID-19 susceptibility and host viral response.
Posttraumatic stress disorder (PTSD) is a stress-related mental disorder and develops after exposure to life-threatening traumatic experiences. The risk factors of PTSD included genetic factors; alterations in hypothalamic-pituitary-adrenal (HPA) axis; neurotrophic, serotonergic, dopaminergic, and catecholaminergic systems; and a variety of environmental factors, such as war, accident, natural disaster, pandemic, physical, or sexual abuse, that cause stress or trauma in individuals. To be able to understand the molecular background of PTSD, rodent animal models are widely used by researchers. When looking for a solution for PTSD, it is important to consider preexisting genetic risk factors and physiological, molecular, and biochemical processes caused by trauma that may cause susceptibility to this disorder. In studies, it is reported that epigenetic mechanisms play important roles in the biological response affected by environmental factors, as well as the task of programming cell identity. In this article, we provided an overview of the role of epigenetic modifications in understanding the biology of PTSD. We also summarized the data from animal studies and their importance during the investigation of PTSD. This study shed light on the epigenetic background of stress and PTSD.
This literature review described the genetic and biochemical factors that may have been overlooked in the formulation of vaccines and that most likely underlie possible issues with mass vaccination.
Background Autism is one of the most complex, heterogeneous neurological disorders. It is characterized mainly by abnormal communication, impaired social interaction, and restricted behaviors. Prevalence of autism is not clear in Indian population.
Aim The present study hypothesized that Y chromosome plays role in sex bias of autism in Indian autistic population. To investigate our hypothesis, we underwent genetic analysis of neuroligin 4Y [NLGN4Y] gene by sequencing 85 male autistic children after screening large population of 1,870 mentally ill children from North Karnataka region of India.
Result Detailed sequencing of the single targeted gene revealed nine variants including, one novel missense mutation and eight synonymous variants; this accounts for 88.9% of synonymous variants. A single novel missense mutation is predicted to be nonpathogenic on the functions of neuroligin4Y protein but it slightly affects the local configuration by altering the original structure of a protein by changing charge and size of amino acid.
Conclusion Probably NLGN4Y gene may not be the risk factor for autism in male children in Indian autistic population. Functional analysis was an important limitation of our study. Therefore, detailed functional analysis is necessary to determine the exact role of novel missense mutation of neuroligin 4Y [NLGN4Y] gene especially in the male predominance of autism in Indian autistic population.
Background Cleidocranial dysplasia (CCD, #MIM119600) is an autosomal-dominant skeletal dysplasia characterized by delayed closure of the cranial sutures, aplasia, or hypoplasia of the clavicles and dental abnormalities. These findings were accompanied by mobile and drooping shoulders, frontal and parietal bossing, hypertelorism, brachycephaly, short stature, supernumerary, and late erupting teeth. Radiographic studies can reveal involvement of multiple bones including skull, chest, pelvis, and limbs. CCD can be diagnosed with clinical and radiological evaluation and validated by molecular studies. Heterozygous loss of function RUNX2 gene, which plays an important role in osteogenesis and differentiation of precursor cells, causes CCD phenotype.
Methods In this article, we reported five cases from three unrelated families with CCD phenotype. All exons and exonic-intronic boundary regions of RUNX2 gene from five patients were analyzed by polymerase chain reaction amplification and direct Sanger-sequencing.
Results Our patients had classical CCD phenotype and we detected three different previously described mutations including c.1171C > T, IVS4 + 4delAAGT and c.676G > A. However, nail dysplasia has never been associated with these mutations. Our patients had varying degrees of nail dysplasia. Two of three mutations are related with Runt DNA-binding domain of RUNX2 protein in Wnt signaling and c.1171C > T had effect on proline/serine/threonine-rich (PST) domain. Recently, Wnt signaling pathway was presented as a key regulator of digit and nail differentiation. Our data suggest that RUNX2 gene may have an essential role on embryogenesis of nails, probably by protecting their integrity.
The prenatal diagnosis of congenital heart disease (CHD) is important because of mortality risk. The onset of CHD varies, and depending on the malformation type, the risk of aneuploidy is changed. To identify possible genetic alterations in CHD, G-banding, chromosomal microarray or if needed DNA mutation analysis and direct sequence analysis should be planned.
In present study, to identify genetic alterations, cell culture, karyotype analysis, and single nucleotide polymorphism, array analyses were conducted on a total 950 samples. Interventional prenatal genetic examination was performed on 23 (2, 4%, 23/950) fetal CHD cases. Chromosomal abnormalities were detected in 5 out of 23 cases (21, 7%). Detected chromosomal abnormalities were 10q23.2 deletion, trisomy 18, 8p22.3-p23.2 deletion, 8q21.3-q24.3 duplication, 11q24.2q24.5 (9 Mb) deletion, and 8p22p12 (16.8 Mb) deletion. Our study highlights the importance of genetic testing in CHD.
Calpainopathy is caused by mutations in the CAPN3. There is only one clinical and genetic study of CAPN3 from India and none from South India. A total of 72 (male[M]:female [F] = 34:38) genetically confirmed probands from 72 independent families are included in this study. Consanguinity was present in 54.2%. The mean age of onset and duration of symptoms are 13.5 ± 6.4 and 6.3 ± 4.7 years, respectively. Positive family history occurred in 23.3%. The predominant initial symptoms were proximal lower limb weakness (52.1%) and toe walking (20.5%). At presentation, 97.2% had hip girdle weakness, 69.4% had scapular winging, and 58.3% had contractures. Follow-up was available in 76.4%, and 92.7% were ambulant at a mean age of 23.7 ± 7.6 years and duration of 4.5 years, remaining 7.3% became wheelchair-bound at 25.5 ± 5.7 years of age (mean duration = 13.5 ± 4.6), 4.1% were aged more than 40 years (duration range = 5-20). The majority remained ambulant 10 years after disease onset. Next-generation sequencing (NGS) detected 47 unique CAPN3 variants in 72 patients, out of which 19 are novel. Missense variants were most common occurring in 59.7% (homozygous = 29; Compound heterozygous = 14). In the remaining 29 patients (40.3%), at least one suspected loss of function variant was present. Common recurrent variants were c.2051-1G > T and c.2338G > C in 9.7%, c.1343G > A, c.802-9G > A, and c.1319G > A in 6.9% and c.1963delC in 5.5% of population. Large deletions were observed in 4.2%. Exon 10 mutations accounted for 12 patients (16.7%). Our study highlights the efficiency of NGS technology in screening and molecular diagnosis of limb-girdle muscular dystrophy with recessive form (LGMDR1) patients in India.
Objective A significant number of genetic variations have been identified in chromosome 22, using molecular genetic techniques. Various genomic disorders on chromosome 22, including cat's eye syndrome caused by extra copies of the proximal region of the 22q chromosome, are now well-defined. Our aim in the study was to show phenotypic variability associated with rearrangements of the 22q chromosomal region.
Methods We focused our study on clinical aspects of these disorders, including genetic testing, genotype-phenotype correlation, and potential treatments. A total of 998 patients were referred for genetic analysis (Karyotyping, MLPA, array-CGH) during January 2015 to February 2020 because of intellectual deficiency, behavior issues, and/or multiple congenital abnormalities in several genetics departments. Informed consent was obtained from all the patients and/or their parents.
Results 22q11.21 or 22q13.33 microdeletions and 22q11.22-q11.23 microduplication were identified in 31 patients out of referrals. The 22q aberrations were detected in 31/998 patients, giving a prevalence of 3.1%. In this study, 18 patients with 22q11.2 (LCR22A-H) deletion, three patients with 22q13.31 deletion, 9 patients with 22q11.2 duplication and one patient with 22q13.31 duplication were identified. We report on the clinical and molecular characterization of 31 individuals with distal deletions and duplications of chromosome 22q.
Conclusions The current study demonstrated in the largest postnatal case series reporting the whole spectrum of atypical phenotypic and genotypic variations at 22q. We believe that when all the phenotypic differences are taken into account, various anomalies including developmental delay and intellectual disability might be considered as an indication to search for aberrations of 22q along with congenital heart diseases.
This article at hand described a 4-year-old child patient who initially presented with the symptoms of toe walking. As part of the diagnostic process, the patient was genetically tested to find the cause of the gait anomaly. The genetic test found a mutation in the KCNC3 gene. The variant c.1268G > A; p.Arg423. His was found in a heterozygotic state. This variant is frequently described as a cause for spinocerebellar ataxia type 13 (SCA13) in the literature. Apart from toe walking as the most pronounced symptom, the patient displayed an instable gait with frequent falls and delayed speech development. The genetic test to determine the cause of the gait anomaly successfully diagnosed the patient with a previously undiscovered SCA13 and subsequently enabled the recommendation of personalized further treatment.