Exome sequencing in a Pakistani male infertility cohort: perspective on molecular diagnosis, genetic heterogeneity, and diagnostic yield.

Male infertility affects a significant number of couples worldwide, yet the precise causes and genetic mechanisms underlying this condition remain largely unknown. To investigate the monogenic causes of primary male infertility, we performed exome sequencing (ES) in a cohort of 100 unrelated Pakistani male patients with non-obstructive, non-syndromic primary infertility. ES identified potential causal variants in established infertility-associated genes in 17/100 patients, resulting in a diagnostic yield of 17%.

Evidence That Dmrta2 Acts through Repression of in Cortical Patterning and Identification of a Mutation Impairing DNA Recognition Associated with Microcephaly in Human.

Dmrta2 (also designated Dmrt5) is a transcriptional regulator expressed in cortical progenitors in a caudomedial/rostrolateral gradient with important roles at different steps of cortical development. Dmrta2 has been suggested to act in cortex development mainly by differential suppression of and other homeobox transcription factors such as the ventral telencephalic regulator , which remains to be fully demonstrated. Here we have addressed the epistatic relation between Pax6 and Dmrta2 by comparing phenotypes in mutant embryos or embryos overexpressing both genes in various allelic combinations.

Further evidence of biallelic NAV3 variants associated with recessive neurodevelopmental disorder with dysmorphism, developmental delay, intellectual disability, and behavioral abnormalities.

Neuron navigators (NAVs) are cytoskeleton-associated proteins well known for their role in axonal guidance, neuronal migration, and neurite growth necessary for neurodevelopment. Neuron navigator 3 (NAV3) is one of the three NAV proteins highly expressed in the embryonic and adult brain. However, the role of the NAV3 gene in human disease is not well-studied.

Clinical and genetic characterization of a progressive RBL2-associated neurodevelopmental disorder.

Retinoblastoma (RB) proteins are highly conserved transcriptional regulators that play important roles during development by regulating cell-cycle gene expression. RBL2 dysfunction has been linked to a severe neurodevelopmental disorder. However, to date, clinical features have been described in only six individuals carrying five biallelic predicted loss-of-function (pLOF) variants.

Generation of a ZEB2 deficient human iPSC line (KICRi002A-4).

The transcription factor ZEB2 is essential for early embryonic development. Using CRISPR/Cas9, we generated a ZEB2 deficient human iPSC cell line (KICRi002A-4), carrying a homozygous 790 bp deletion in ZEB2 that involves part of exon 5, intron 5 and part of exon 6. The deletion leads to markedly reduced levels of a truncated ZEB2 transcript.

Exome sequencing in four families with neurodevelopmental disorders: genotype-phenotype correlation and identification of novel disease-causing variants in VPS13B and RELN.

Neurodevelopmental disorders (NDDs) are a clinically and genetically heterogeneous group of early-onset pediatric disorders that affect the structure and/or function of the central or peripheral nervous system. Achieving a precise molecular diagnosis for NDDs may be challenging due to the diverse genetic underpinnings and clinical variability. In the current study, we investigated the underlying genetic cause(s) of NDDs in four unrelated Pakistani families.

Genetic Investigation of Consanguineous Pakistani Families Segregating Rare Spinocerebellar Disorders.

Spinocerebellar disorders are a vast group of rare neurogenetic conditions, generally characterized by overlapping clinical symptoms including progressive cerebellar ataxia, spastic paraparesis, cognitive deficiencies, skeletal/muscular and ocular abnormalities. The objective of the present study is to identify the underlying genetic causes of the rare spinocerebellar disorders in the Pakistani population. Herein, nine consanguineous families presenting different spinocerebellar phenotypes have been investigated using whole exome sequencing.

Genetic association of vitamin D receptor gene with female infertility.

Background: Infertility is defined as failure to achieve a clinical pregnancy after 12 months of unprotected intercourse. It affects 15% of couples globally and 22% of couples within Pakistan. Female infertility can be caused by numerous genetic or environmental factors including hormone imbalances and exposure to chemicals or radiation.

A homozygous founder variant in PDE2A causes paroxysmal dyskinesia with intellectual disability.

Intellectual developmental disorder with paroxysmal dyskinesia or seizures (IDDPADS, OMIM#619150) is an ultra-rare childhood-onset autosomal recessive movement disorder manifesting paroxysmal dyskinesia, global developmental delay, impaired cognition, progressive psychomotor deterioration and/or drug-refractory seizures. We investigated three consanguineous Pakistani families with six affected individuals presenting overlapping phenotypes partially consistent with the reported characteristics of IDDPADS. Whole exome sequencing identified a novel missense variant in Phosphodiesterase 2A (PDE2A): NM_002599.

ZEB2 haploinsufficient Mowat-Wilson syndrome induced pluripotent stem cells show disrupted GABAergic transcriptional regulation and function.

Mowat-Wilson syndrome (MWS) is a severe neurodevelopmental disorder caused by heterozygous variants in the gene encoding transcription factor . Affected individuals present with structural brain abnormalities, speech delay and epilepsy. In mice, conditional loss of Zeb2 causes hippocampal degeneration, altered migration and differentiation of GABAergic interneurons, a heterogeneous population of mainly inhibitory neurons of importance for maintaining normal excitability.

A Novel Nonsense Variant in Causes Autosomal Recessive Spinocerebellar Ataxia 13 in a Consanguineous Pakistani Family.

Autosomal recessive spinocerebellar ataxia-13 (SCAR13) is an ultra-rare disorder characterized by slowly progressive cerebellar ataxia, cognitive deficiencies, and skeletal and oculomotor abnormalities. The objective of this case report is to expand the clinical and molecular spectrum of SCAR13. We investigated a consanguineous Pakistani family with four patients partially presenting with clinical features of SCAR13 using whole exome sequencing.

The SARS-CoV-2 differential genomic adaptation in response to varying UVindex reveals potential genomic resources for better COVID-19 diagnosis and prevention.

Coronavirus disease 2019 (COVID-19) has been a pandemic disease reported in almost every country and causes life-threatening, severe respiratory symptoms. Recent studies showed that various environmental selection pressures challenge the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infectivity and, in response, the virus engenders new mutations, leading to the emergence of more virulent strains of WHO concern. Advance prediction of the forthcoming virulent SARS-CoV-2 strains in response to the principal environmental selection pressures like temperature and solar UV radiation is indispensable to overcome COVID-19.

MCPH1: A Novel Case Report and a Review of the Literature.

Microcephaly primary hereditary (MCPH) is a congenital disease characterized by nonsyndromic reduction in brain size due to impaired neurogenesis, often associated with a variable degree of intellectual disability (ID). The genetic etiology of MCPH is heterogeneous and comprises more than 20 loci, nearly all following a recessive inheritance pattern. The first causative gene identified, or , encodes a centrosomal protein that modulates chromosome condensation and cell cycle progression.

Rare Pathogenic Variants in Genes Implicated in Glutamatergic Neurotransmission Pathway Segregate with Schizophrenia in Pakistani Families.

Schizophrenia is a disabling neuropsychiatric disorder of adulthood onset with high heritability. Worldwide collaborations have identified an association of ~270 common loci, with small individual effects and hence weak clinical implications. The recent technological feasibility of exome sequencing enables the identification of rare variants of high penetrance that refine previous findings and improve risk assessment and prognosis.

Syndromic RNA polymerase II insufficiency: Generation of a human induced pluripotent stem cell line (UUIGPi002A-5) with a heterozygous disruption of POLR2A.

Heterozygous variants in POLR2A, encoding the largest subunit of RNA polymerase II, cause severe neurodevelopmental and multisystem abnormalities in humans. Using CRISPR/Cas9 we generated the human iPSC line KICRi002A-5 with a heterozygous truncating 4 bp insertion in exon 5 of the POLR2A gene. Analysis using qRT-PCR confirmed reduced POLR2A mRNA in KICRi002A-5 vs.

Modifier Genes in Microcephaly: A Report on , , and Variants Exacerbating Disease Caused by Biallelic Mutations of and .

Congenital microcephaly is the clinical presentation of significantly reduced head circumference at birth. It manifests as both non-syndromic-microcephaly primary hereditary (MCPH)-and syndromic forms and shows considerable inter- and intrafamilial variability. It has been hypothesized that additional genetic variants may be responsible for this variability, but data are sparse.

Monoallelic and bi-allelic variants in NCDN cause neurodevelopmental delay, intellectual disability, and epilepsy.

Neurochondrin (NCDN) is a cytoplasmatic neural protein of importance for neural growth, glutamate receptor (mGluR) signaling, and synaptic plasticity. Conditional loss of Ncdn in mice neural tissue causes depressive-like behaviors, impaired spatial learning, and epileptic seizures. We report on NCDN missense variants in six affected individuals with variable degrees of developmental delay, intellectual disability (ID), and seizures.

Generation of two human iPSC lines (UUIGPi013-A and UUIPGi014-A) from cases with Down syndrome and full trisomy for chromosome 21 (T21).

Down syndrome (DS) is caused by trisomy for chromosome 21 (T21). We generated two induced pluripotent stem cell (iPSC) lines from skin fibroblasts of two males with DS using Sendai virus delivery of OCT4, SOX2, KLF4, and c-MYC. Characterization of the two iPSC lines, UUIGPi013-A and UUIPGi014-A, showed that they are genetically stable with a 47,XY,+21 karyotype.

RRP7A links primary microcephaly to dysfunction of ribosome biogenesis, resorption of primary cilia, and neurogenesis.

Primary microcephaly (MCPH) is characterized by reduced brain size and intellectual disability. The exact pathophysiological mechanism underlying MCPH remains to be elucidated, but dysfunction of neuronal progenitors in the developing neocortex plays a major role. We identified a homozygous missense mutation (p.

Aberrant splicing due to a novel RPS7 variant causes Diamond-Blackfan Anemia associated with spontaneous remission and meningocele.

Diamond-Blackfan Anemia (DBA) is a congenital pure red cell aplasia caused by heterozygous variants in ribosomal protein genes. The hematological features associated with DBA are highly variable and non-hematological abnormalities are common. We report herein on an affected mother and her daughter presenting with transfusion-dependent anemia.

Generation of a human Neurochondrin deficient iPSC line KICRi002-A-3 using CRISPR/Cas9.

The role of Neurochondrin (NCDN) in humans is not well understood. Mice with a conditional Ncdn knock-out show epileptic seizures, depressive-like behaviours and impaired spatial learning. Using CRISPR/Cas9, we generated a Neurochondrin deficient human iPSC line KICRi002-A-3 carrying a homozygous 752 bp deletion / 2 bp insertion in the NCDN gene.

Incontinentia pigmenti: Generation of an IKBKG deficient human iPSC line (KICRi002-A-1) on a 46,XY background using CRISPR/Cas9.

Incontinentia pigmenti (IP) is an X-linked dominant neuroectodermal dysplasia caused by loss-of-function mutations in the IKBKG gene. Using CRISPR/Cas9 technology, we generated an IKBKG knock-out iPSC line (KICRi002-A-1) on a 46,XY background. The iPSC line showed a normal karyotype, expressed pluripotency markers and exhibited capability to differentiate into the three germ layers in vitro.