@article {549, title = {Global genetic insight contributed by consanguineous Pakistani families segregating hearing loss.}, journal = {Hum Mutat}, volume = {40}, year = {2019}, month = {2019 Jan}, pages = {53-72}, abstract = {

Consanguineous Pakistani pedigrees segregating deafness have contributed decisively to the discovery of 31 of the 68 genes associated with nonsyndromic autosomal recessive hearing loss (HL) worldwide. In this study, we utilized genome-wide genotyping, Sanger and exome sequencing to identify 163 DNA variants in 41 previously reported HL genes segregating in 321 Pakistani families. Of these, 70 (42.9\%) variants identified in 29 genes are novel. As expected from genetic studies of disorders segregating in consanguineous families, the majority of affected individuals (94.4\%) are homozygous for HL-associated variants, with the other variants being compound heterozygotes. The five most common HL genes in the Pakistani population are SLC26A4, MYO7A, GJB2, CIB2 and HGF, respectively. Our study provides a profile of the genetic etiology of HL in Pakistani families, which will allow for the development of more efficient genetic diagnostic tools, aid in accurate genetic counseling, and guide application of future gene-based therapies. These findings are also valuable in interpreting pathogenicity of variants that are potentially associated with HL in individuals of all ancestries. The Pakistani population, and its infrastructure for studying human genetics, will continue to be valuable to gene discovery for HL and other inherited disorders.

}, issn = {1098-1004}, doi = {10.1002/humu.23666}, author = {Richard, Elodie M and Santos-Cortez, Regie Lyn P and Faridi, Rabia and Rehman, Atteeq U and Lee, Kwanghyuk and Shahzad, Mohsin and Acharya, Anushree and Khan, Asma A and Imtiaz, Ayesha and Chakchouk, Imen and Takla, Christina and Abbe, Izoduwa and Rafeeq, Maria and Liaqat, Khurram and Chaudhry, Taimur and Bamshad, Michael J and Nickerson, Deborah A and Schrauwen, Isabelle and Khan, Shaheen N and Morell, Robert J and Zafar, Saba and Ansar, Muhammad and Ahmed, Zubair M and Ahmad, Wasim and Riazuddin, Sheikh and Friedman, Thomas B and Leal, Suzanne M and Riazuddin, Saima} } @article {660, title = {Identification of CACNA1D variants associated with sinoatrial node dysfunction and deafness in additional Pakistani families reveals a clinical significance.}, journal = {J Hum Genet}, volume = {64}, year = {2019}, month = {2019 Feb}, pages = {153-160}, abstract = {

Sinoatrial node dysfunction and deafness (SANDD) syndrome is rare and characterized by a low heart beat and severe-to-profound deafness. Additional features include fatigue, dizziness, and episodic syncope. The sinoatrial node (SAN) drives heart automaticity and continuously regulates heart rate. The CACNA1D gene encoding the Ca1.3 protein expressed in inner hair cells, atria and SAN, induces loss-of-function in channel activity and underlies SANDD. To date, only one variant c.1208_1209insGGG:p.(G403_V404insG) has been reported for SANDD syndrome. We studied five Pakistani families with SANDD and characterized a new missense variant p.(A376V) in CACNA1D in one family, and further characterized the founder variant p.(G403_V404insG) in four additional pedigrees. We show that affected individuals in the four families which segregate p.(G403_V404insG) share a 1.03 MB haplotype on 3p21.1 suggesting they share a common distant ancestor. In conclusion, we identified new and known variants in CACNA1D in five Pakistani families with SANDD. This study is of clinical importance as the CACNA1D founder variant is only observed in families from the Khyber Pakhtunkhwa (KPK) province, in Pakistan. Therefore, screening patients with congenital deafness for SAN dysfunction in this province could ensure adequate follow-up and prevent cardiac failure associated with SAN.

}, keywords = {Adolescent, Calcium Channels, L-Type, Deafness, Female, Heart Diseases, Humans, Male, Mutation, Pakistan, Pedigree, Prognosis, Sinoatrial Node}, issn = {1435-232X}, doi = {10.1038/s10038-018-0542-8}, author = {Liaqat, Khurram and Schrauwen, Isabelle and Raza, Syed Irfan and Lee, Kwanghyuk and Hussain, Shabir and Chakchouk, Imen and Nasir, Abdul and Acharya, Anushree and Abbe, Izoduwa and Umair, Muhammad and Ansar, Muhammad and Ullah, Irfan and Shah, Khadim and Bamshad, Michael J and Nickerson, Deborah A and Ahmad, Wasim and Leal, Suzanne M} } @article {512, title = {Confirmation of the Role of DHX38 in the Etiology of Early-Onset Retinitis Pigmentosa.}, journal = {Invest Ophthalmol Vis Sci}, volume = {59}, year = {2018}, month = {2018 09 04}, pages = {4552-4557}, abstract = {

Purpose: Retinitis pigmentosa (RP) is a genetically heterogeneous trait with autosomal-recessive (ar) inheritance underlying 50\% of genetic disease cases. Sixty-one arRP genes have been identified, and recently, DHX38 has been reported as a potential candidate gene for arRP with only a single family reported with a variant of unknown significance. We identified a missense variant in DHX38 that co-segregates with the arRP phenotype in two Pakistani families confirming the involvement of DHX38 in the etiology of early-onset RP.

Methods: Exome sequencing was performed using two DNA samples from affected members of Pakistani families (MA88 and MA157) with early onset arRP. Sanger sequencing of DNA samples from all family members confirmed the segregation of candidate variant within both families.

Results: A novel missense DHX38 variant c.971G>A; p.(Arg324Gln) was identified which segregates with the arRP phenotype and yielded a logarithm of the odds (LOD) score of 5.0 and 4.3 for families MA88 and MA157, respectively. This variant is predicted to be conserved and deleterious by several bioinformatics tools.

Conclusions: We identified a second deleterious DHX38 variant that segregates with arRP in two families, providing additional evidence that DHX38 is involved in RP etiology. DHX38 encodes for pre-mRNA splicing factor PRP16, which is important in catalyzing pre-mRNA splicing.

}, keywords = {Adolescent, Adult, Cataract, Computational Biology, DEAD-box RNA Helicases, Female, Genes, Recessive, Genetic Association Studies, Genetic Linkage, Humans, Male, Mutation, Missense, Nucleotide Mapping, Ophthalmoscopy, Pedigree, Retinitis Pigmentosa, RNA Splicing Factors, Sequence Analysis, DNA, Whole Exome Sequencing, Young Adult}, issn = {1552-5783}, doi = {10.1167/iovs.18-23849}, author = {Latif, Zahid and Chakchouk, Imen and Schrauwen, Isabelle and Lee, Kwanghyuk and Santos-Cortez, Regie Lyn P and Abbe, Izoduwa and Acharya, Anushree and Jarral, Afeefa and Ali, Imran and Ullah, Ehsan and Khan, Muhammad Nasim and Ali, Ghazanfar and Tahir, Tufail Hussain and Bamshad, Michael J and Nickerson, Deborah A and Ahmad, Wasim and Ansar, Muhammad and Leal, Suzanne M} } @article {498, title = {Novel candidate genes and variants underlying autosomal recessive neurodevelopmental disorders with intellectual disability.}, journal = {Hum Genet}, volume = {137}, year = {2018}, month = {2018 Sep}, pages = {735-752}, abstract = {

Identification of Mendelian genes for neurodevelopmental disorders using exome sequencing to study autosomal recessive (AR) consanguineous pedigrees has been highly successful. To identify causal variants for syndromic and non-syndromic intellectual disability (ID), exome sequencing was performed using DNA samples from 22 consanguineous Pakistani families with ARID, of which 21 have additional phenotypes including microcephaly. To aid in variant identification, homozygosity mapping and linkage analysis were performed. DNA samples from affected family member(s) from every pedigree underwent exome sequencing. Identified rare damaging exome variants were tested for co-segregation with ID using Sanger sequencing. For seven ARID families, variants were identified in genes not previously associated with ID, including: EI24, FXR1 and TET3 for which knockout mouse models have brain defects; and CACNG7 and TRAPPC10 where cell studies suggest roles in important neural pathways. For two families, the novel ARID genes CARNMT1 and GARNL3 lie within previously reported ID microdeletion regions. We also observed homozygous variants in two ID candidate genes, GRAMD1B and TBRG1, for which each has been previously reported in a single family. An additional 14 families have homozygous variants in established ID genes, of which 11 variants are novel. All ARID genes have increased expression in specific structures of the developing and adult human brain and 91\% of the genes are differentially expressed in utero or during early childhood. The identification of novel ARID candidate genes and variants adds to the knowledge base that is required to further understand human brain function and development.

}, keywords = {Adult, Consanguinity, Family, Female, Genes, Recessive, Genetic Markers, Humans, Intellectual Disability, Male, Middle Aged, Mutation, Neurodevelopmental Disorders, Pedigree}, issn = {1432-1203}, doi = {10.1007/s00439-018-1928-6}, author = {Santos-Cortez, Regie Lyn P and Khan, Valeed and Khan, Falak Sher and Mughal, Zaib-Un-Nisa and Chakchouk, Imen and Lee, Kwanghyuk and Rasheed, Memoona and Hamza, Rifat and Acharya, Anushree and Ullah, Ehsan and Saqib, Muhammad Arif Nadeem and Abbe, Izoduwa and Ali, Ghazanfar and Hassan, Muhammad Jawad and Khan, Saadullah and Azeem, Zahid and Ullah, Irfan and Bamshad, Michael J and Nickerson, Deborah A and Schrauwen, Isabelle and Ahmad, Wasim and Ansar, Muhammad and Leal, Suzanne M} } @article {632, title = {Sequence variants in nine different genes underlying rare skin disorders in 10 consanguineous families.}, journal = {Int J Dermatol}, volume = {56}, year = {2017}, month = {2017 Dec}, pages = {1406-1413}, abstract = {

BACKGROUND: Genodermatoses represent genetic anomalies of skin tissues including hair follicles, sebaceous glands, eccrine glands, nails, and teeth. Ten consanguineous families segregating various genodermatosis phenotypes were investigated in the present study.

METHODS: Homozygosity mapping, exome, and Sanger sequencing were employed to search for the disease-causing variants in the 10 families.

RESULTS: Exome sequencing identified seven homozygous sequence variants in different families, including: c.27delT in FERMT1; c.836delA in ABHD5; c.2453C>T in ERCC5; c.5314C>T in COL7A1; c.1630C>T in ALOXE3; c.502C>T in PPOX; and c.10G>T in ALDH3A2. Sanger sequencing revealed three homozygous variants: c.1718~+~2A>G in FERMT1; c.10459A>T in FLG; and c.92delT in the KRT14 genes as the underlying genetic cause of skin phenotypes.

CONCLUSION: This study supports the use of exome sequencing as a powerful, efficient tool for identifying genes that underlie rare monogenic skin disorders.

}, keywords = {1-Acylglycerol-3-Phosphate O-Acyltransferase, Aldehyde Oxidoreductases, Blister, Collagen Type VII, Consanguinity, DNA Mutational Analysis, DNA-Binding Proteins, Endonucleases, Epidermolysis Bullosa, Epidermolysis Bullosa Dystrophica, Epidermolysis Bullosa Simplex, Exome, Female, Flavoproteins, Homozygote, Humans, Ichthyosiform Erythroderma, Congenital, Ichthyosis Vulgaris, Ichthyosis, Lamellar, INDEL Mutation, Intermediate Filament Proteins, Keratin-14, Lipid Metabolism, Inborn Errors, Lipoxygenase, Male, Membrane Proteins, Mitochondrial Proteins, Muscular Diseases, Neoplasm Proteins, Nuclear Proteins, Pedigree, Periodontal Diseases, Phenotype, Photosensitivity Disorders, Porphyria, Variegate, Protoporphyrinogen Oxidase, Rare Diseases, Sjogren-Larsson Syndrome, Skin Diseases, Genetic, Transcription Factors, Xeroderma Pigmentosum}, issn = {1365-4632}, doi = {10.1111/ijd.13778}, author = {Shah, Khadim and Mehmood, Sabba and Jan, Abid and Abbe, Izoduwa and Hussain Ali, Raja and Khan, Anwar and Chishti, Muhammad S and Lee, Kwanghyuk and Ahmad, Farooq and Ansar, Muhammad and Shahzad, Shaheen and Nickerson, Deborah A and Bamshad, Michael J and Coucke, Paul J and Santos-Cortez, Regie L P and Spritz, Richard A and Leal, Suzanne M and Ahmad, Wasim} } @article {100, title = {Expansion of the spectrum of ITGB6-related disorders to adolescent alopecia, dentogingival abnormalities and intellectual disability.}, journal = {Eur J Hum Genet}, volume = {24}, year = {2016}, month = {2016 08}, pages = {1223-7}, abstract = {

Alopecia with mental retardation (APMR) is a very rare disorder. In this study, we report on a consanguineous Pakistani family (AP91) with mild-to-moderate intellectual disability, adolescent alopecia and dentogingival abnormalities. Using homozygosity mapping, linkage analysis and exome sequencing, we identified a novel rare missense variant c.898G>A (p.(Glu300Lys)) in ITGB6, which co-segregates with the phenotype within the family and is predicted to be deleterious. Structural modeling shows that Glu300 lies in the β-propeller domain, and is surrounded by several residues that are important for heterodimerization with α integrin. Previous studies showed that ITGB6 variants can cause amelogenesis imperfecta in humans, but patients from family AP91 who are homozygous for the c.898G>A variant present with neurological and dermatological features, indicating a role for ITGB6 beyond enamel formation. Our study demonstrates that a rare deleterious variant within ITGB6 causes not only dentogingival anomalies but also intellectual disability and alopecia.

}, keywords = {Adolescent, Adult, Alopecia, Child, Female, Humans, Integrin beta Chains, Intellectual Disability, Male, Mutation, Missense, Pedigree, Phenotype, Protein Domains, Syndrome, Tooth Abnormalities}, issn = {1476-5438}, doi = {10.1038/ejhg.2015.260}, author = {Ansar, Muhammad and Jan, Abid and Santos-Cortez, Regie Lyn P and Wang, Xin and Suliman, Muhammad and Acharya, Anushree and Habib, Rabia and Abbe, Izoduwa and Ali, Ghazanfar and Lee, Kwanghyuk and Smith, Joshua D and Nickerson, Deborah A and Shendure, Jay and Bamshad, Michael J and Ahmad, Wasim and Leal, Suzanne M} } @article {83, title = {Mitral regurgitation as a phenotypic manifestation of nonphotosensitive trichothiodystrophy due to a splice variant in MPLKIP.}, journal = {BMC Med Genet}, volume = {17}, year = {2016}, month = {2016 Feb 16}, pages = {13}, abstract = {

BACKGROUND: Nonphotosensitive trichothiodystrophy (TTDN) is a rare autosomal recessive disorder of neuroectodermal origin. The condition is marked by hair abnormalities, intellectual impairment, nail dystrophies and susceptibility to infections but with no UV sensitivity.

METHODS: We identified three consanguineous Pakistani families with varied TTDN features and used homozygosity mapping, linkage analysis, and Sanger and exome sequencing in order to identify pathogenic variants. Haplotype analysis was performed and haplotype age estimated. A splicing assay was used to validate the effect of the MPLKIP splice variant on expression.

RESULTS: Affected individuals from all families exhibit several TTDN features along with a heart-specific feature, i.e. mitral regurgitation. Exome sequencing in the probands from families ED168 and ED241 identified a homozygous splice mutation c.339 + 1G > A within MPLKIP. The same splice variant co-segregates with TTDN in a third family ED210. The MPLKIP splice variant was not found in public databases, e.g. the Exome Aggregation Consortium, and in unrelated Pakistani controls. Functional analysis of the splice variant confirmed intron retention, which leads to protein truncation and loss of a phosphorylation site. Haplotype analysis identified a 585.1-kb haplotype which includes the MPLKIP variant, supporting the existence of a founder haplotype that is estimated to be 25,900 years old.

CONCLUSION: This study extends the allelic and phenotypic spectra of MPLKIP-related TTDN, to include a splice variant that causes cardiomyopathy as part of the TTDN phenotype.

}, keywords = {Adaptor Proteins, Signal Transducing, Adolescent, Adult, Alleles, Asian Continental Ancestry Group, Child, Cloning, Molecular, Exome, Female, Genetic Linkage, Haplotypes, HEK293 Cells, Homozygote, Humans, Introns, Male, Mitral Valve Insufficiency, Pakistan, Pedigree, Phenotype, Polymorphism, Single Nucleotide, RNA Splicing, Sequence Analysis, DNA, Trichothiodystrophy Syndromes, Young Adult}, issn = {1471-2350}, doi = {10.1186/s12881-016-0275-5}, author = {Shah, Khadim and Ali, Raja Hussain and Ansar, Muhammad and Lee, Kwanghyuk and Chishti, Muhammad Salman and Abbe, Izoduwa and Li, Biao and Smith, Joshua D and Nickerson, Deborah A and Shendure, Jay and Coucke, Paul J and Steyaert, Wouter and Bamshad, Michael J and Santos-Cortez, Regie Lyn P and Leal, Suzanne M and Ahmad, Wasim} } @article {152, title = {Rare A2ML1 variants confer susceptibility to otitis media.}, journal = {Nat Genet}, volume = {47}, year = {2015}, month = {2015 Aug}, pages = {917-20}, abstract = {

A duplication variant within the middle ear-specific gene A2ML1 cosegregates with otitis media in an indigenous Filipino pedigree (LOD score = 7.5 at reduced penetrance) and lies within a founder haplotype that is also shared by 3 otitis-prone European-American and Hispanic-American children but is absent in non-otitis-prone children and >62,000 next-generation sequences. We identified seven additional A2ML1 variants in six otitis-prone children. Collectively, our studies support a role for A2ML1 in the pathophysiology of otitis media.

}, keywords = {alpha-Macroglobulins, Animals, Base Sequence, Child, Cochlea, Exome, Family Health, Female, Gene Duplication, Gene Frequency, Genetic Predisposition to Disease, Genotype, Haplotypes, Humans, Male, Mice, Inbred C57BL, Models, Molecular, Otitis Media, Pedigree, Principal Component Analysis, Protein Conformation, Sequence Analysis, DNA}, issn = {1546-1718}, doi = {10.1038/ng.3347}, author = {Santos-Cortez, Regie Lyn P and Chiong, Charlotte M and Reyes-Quintos, Ma Rina T and Tantoco, Ma Leah C and Wang, Xin and Acharya, Anushree and Abbe, Izoduwa and Giese, Arnaud P and Smith, Joshua D and Allen, E Kaitlynn and Li, Biao and Cutiongco-de la Paz, Eva Maria and Garcia, Marieflor Cristy and Llanes, Erasmo Gonzalo D V and Labra, Patrick John and Gloria-Cruz, Teresa Luisa I and Chan, Abner L and Wang, Gao T and Daly, Kathleen A and Shendure, Jay and Bamshad, Michael J and Nickerson, Deborah A and Patel, Janak A and Riazuddin, Saima and Sale, Michele M and Chonmaitree, Tasnee and Ahmed, Zubair M and Abes, Generoso T and Leal, Suzanne M} }