A Novel Frameshift Mutation in Abnormal Spindle-Like Microcephaly (ASPM) Gene in an Iranian Patient with Primary Microcephaly: A Case Report

2020 ◽  
Author(s):  
Afsaneh BAZGIR ◽  
Mehdi AGHA GHOLIZADEH ◽  
Faezeh SARVAR ◽  
Zahra PAKZAD
Keyword(s):  
Intellectual Disability ◽  
Frameshift Mutation ◽  
Genetic Disorder ◽  
Normal Function ◽  
Molecular Testing ◽  
Homozygous Mutation ◽  
Primary Microcephaly ◽  
Iranian Patient ◽  
Whole Exome ◽  
Autosomal Recessive Primary Microcephaly

Autosomal recessive primary microcephaly (MCPH) is a rare genetic disorder, leading to the defect of neurogenic brain development. Individuals with MCPH reveal reduced head circumference and intellectual disability. Several MCPH loci have been identified from several populations. Genetic heterogeneity of this disorder represents molecular testing challenge. An 8 yr old female, born from consanguineous parents, was attended to Fardis Central Lab, Alborz, Iran. Based on the reduced circumference and intellectual disability, MCPH was diagnosed. Whole exome sequencing of the patient identified a novel homozygous frameshift mutation (c.2738dupT, p.Cys914fs) in exon 9 Abnormal Spindle-like Microcephaly )ASPM( gene. By Sanger sequencing, segregation analysis showed that both parents were heterozygous carriers for this variant. The novel frameshift mutation likely truncates the protein, resulting in loss of normal function ASPM in homozygous mutation carriers. The study might add a new pathogenic variant in mutations of the ASPM gene as a causative variant in patients with MCPH and might be helpful in genetic counseling of consanguineous families.

scholarly journals Whole exome sequencing identifies a novel homozygous frameshift mutation in the ASPM gene, which causes microcephaly 5, primary, autosomal recessive

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2163
Author(s):  
Desaraju Suresh Bhargav ◽  
N. Sreedevi ◽  
N. Swapna ◽  
Soumya Vivek ◽  
Srinivas Kovvali
Keyword(s):  
Exome Sequencing ◽  
Autosomal Recessive ◽  
Frameshift Mutation ◽  
Protein Gene ◽  
Single Gene ◽  
Primary Microcephaly ◽  
Sequencing Technologies ◽  
Whole Exome ◽  
The Family ◽  
Autosomal Recessive Primary Microcephaly

Microcephaly is a genetically heterogeneous disorder and is one of the frequently notable conditions in paediatric neuropathology which exists either as a single entity or in association with other co-morbidities. More than a single gene is implicated in true microcephaly and the list is growing with the recent advancements in sequencing technologies. Using massive parallel sequencing, we identified a novel frame shift insertion in the abnormal spindle-like microcephaly-associated protein gene in a client with true autosomal recessive primary microcephaly.  Exome sequencing in the present case helped in identifying the true cause behind the disease, which helps in the premarital counselling for the sibling to avoid future recurrence of the disorder in the family.

scholarly journals Whole exome sequencing identifies a novel mutation in ASPM and ultra-rare mutation in CDK5RAP2 causing Primary microcephaly in consanguineous Pakistani families

2021 ◽  
Vol 38 (1) ◽  
Author(s):  
Ehtisham ul Haq Makhdoom ◽  
Haseeb Anwar ◽  
Shahid Mahmood Baig ◽  
Ghulam Hussain
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Novel Mutation ◽  
Speech Impairment ◽  
Primary Microcephaly ◽  
Rare Mutation ◽  
Homozygous Variant ◽  
Whole Exome ◽  
Pakistani Families

Background & Objectives: Primary Microcephaly (MCPH) is a rare neurogenetic disease, manifesting congenitally reduced head circumference and non-progressive intellectual disability (ID). To date, twenty-eight genes with biallelic mutations have been reported for this disorder. The study aimed for molecular genetic characterization of Pakistani families segregating MCPH. Methods: We studied two unrelated consanguineous families (family A and B) presenting >2 patients with diagnostic symptoms of MCPH, born to asymptomatic parents. We employed whole-exome sequencing (WES) of probands to find putative causal mutations. The candidate variants were further confirmed and analyzed for co-segregation by Sanger sequencing of all available members of each family. This study was conducted at Government College University, Faisalabad, Pakistan, and Cologne Center for Genomics (CCG), University of Cologne, Germany; during 2017-2020. Results: We identified a novel homozygous variant c.10097_10098delGA, p.(Gly3366Glufs*19) in exon 26 of ASPM gene in family A which presents with moderate intellectual disability, speech impairment, visual abnormalities, seizures, and ptyalism. Family B was found to segregate nonsense, homozygous variant c.448C>T p.(Arg150*) in CDK5RAP2. The patients also exhibited mild to severe seizures without ptyalism that has not been previously reported in patients with mutations in the CDK5RAP2 gene. Conclusion: We report a novel mutation in ASPM and ultra-rare mutation in the CDK5RAP2 gene, both causing primary microcephaly. The study expands the mutational spectrum of the ASPM gene to 212, and also adds to the clinical spectrum of CDK5RAP2 mutations. It also demonstrated the utility of WES in the investigation and genetic diagnosis of genetically heterogeneous disorders like MCPH. These findings would aid in diagnostic and preventive strategies including carrier screening, cascade testing, and genetic counselling. doi: https://doi.org/10.12669/pjms.38.1.4464 How to cite this:Makhdoom EH, Anwar H, Baig SM, Hussain G. Whole exome sequencing identifies a novel mutation in ASPM and ultra-rare mutation in CDK5RAP2 causing Primary microcephaly in consanguineous Pakistani families. Pak J Med Sci. 2022;38(1):---------.  doi: https://doi.org/10.12669/pjms.38.1.4464 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

scholarly journals Whole Exome Sequencing Identifies Three Novel Mutations in the ASPM Gene From Saudi Families Leading to Primary Microcephaly

2021 ◽  
Vol 8 ◽  
Author(s):  
Muhammad Imran Naseer ◽  
Angham Abdulrahman Abdulkareem ◽  
Osama Yousef Muthaffar ◽  
Sameera Sogaty ◽  
Hiba Alkhatabi ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
Genetic Defect ◽  
Deletion Mutation ◽  
Primary Microcephaly ◽  
Novel Mutations ◽  
Whole Exome ◽  
Novel Variants ◽  
Healthy Control

Autosomal recessive primary microcephaly (MCPH) is a neurodevelopmental defect that is characterized by reduced head circumference at birth along with non-progressive intellectual disability. Till date, 25 genes related to MCPH have been reported so far in humans. The ASPM (abnormal spindle-like, microcephaly-associated) gene is among the most frequently mutated MCPH gene. We studied three different families having primary microcephaly from different regions of Saudi Arabia. Whole exome sequencing (WES) and Sanger sequencing were done to identify the genetic defect. Collectively, three novel variants were identified in the ASPM gene from three different primary microcephaly families. Family 1, showed a deletion mutation leading to a frameshift mutation c.1003del. (p.Val335*) in exon 3 of the ASPM gene and family 2, also showed deletion mutation leading to frameshift mutation c.1047del (p.Gln349Hisfs*18), while in family 3, we identified a missense mutation c.5623A>G leading to a change in protein (p.Lys1875Glu) in exon 18 of the ASPM gene underlying the disorder. The identified respective mutations were ruled out in 100 healthy control samples. In conclusion, we found three novel mutations in the ASPM gene in Saudi families that will help to establish a disease database for specified mutations in Saudi population and will further help to identify strategies to tackle primary microcephaly in the kingdom.

scholarly journals A Novel De Novo Frameshift Mutation in KAT6A Identified by Whole Exome Sequencing

2018 ◽  
Vol 08 (01) ◽  
pp. 010-014 ◽  
Author(s):  
Wafa Alazaizeh ◽  
Asem Alkhateeb
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Brain Magnetic Resonance Imaging ◽  
Comparative Genomic ◽  
Feeding Difficulties ◽  
Whole Exome

AbstractIntellectual disability is a common condition with multiple etiologies. The number of monogenic causes has increased steadily in recent years due to the implementation of next generation sequencing. Here, we describe a 2-year-old boy with global developmental delay and intellectual disability. The child had feeding difficulties since birth. He had delayed motor skills and muscular hypotonia. Brain magnetic resonance imaging revealed diffuse white matter loss and thinning of the corpus callosum. Banded karyotype and comparative genomic hybridization (CGH) array were normal. Whole exome sequencing revealed a novel de novo frameshift mutation c.3390delA (p.Lys1130Asnfs*4) in KAT6A gene (NM_006766.4). The heterozygous mutation was confirmed by Sanger sequencing in the patient and its absence in his parents. KAT6A that encodes a histone acetyltransferase has been recently found to be associated with a neurodevelopmental disorder autosomal dominant mental retardation 32 (OMIM: no. 616268). Features of this disorder are nonspecific, which makes it difficult to characterize the condition based on the clinical symptoms alone. Therefore, our findings confirm the utility of whole exome sequencing to quickly and reliably identify the etiology of such conditions.

scholarly journals Kabuki Syndrome: Identification of Two Novel Variants in KMT2Dand KDM6A

2021 ◽  
pp. 1-9
Author(s):  
Mehrnoosh Khodaeian ◽  
Ehsan Jafarinia ◽  
Fatemeh Bitarafan ◽  
Shohreh Shafeii ◽  
Navid Almadani ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
De Novo ◽  
Genetic Disorder ◽  
Missense Variant ◽  
Kabuki Syndrome ◽  
Functional Studies ◽  
Large Deletions ◽  
Whole Exome ◽  
Functionally Impaired ◽  
And Function

Kabuki syndrome (KS) is a rare genetic disorder characterized by the following 5 crucial symptoms: dysmorphic facial features, growth retardation, skeletal abnormalities, intellectual disability, and dermatoglyphic malformations. Studies show that most of the KS cases are caused by mutations or large deletions in the KMT2D gene, while the other cases show mutations in KDM6A. We studied 2 patients with suspected KS in 2 unrelated families by whole-exome sequencing to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants and check the segregation in other members of the families. Finally, the potential effects of the variants on the structure and function of respective proteins were tested using in silico predictions. Both affected members of the families showed typical manifestations of KS including intellectual disability, developmental delay, and abnormal facial characteristics. A novel heterozygous frameshift variant in the KMT2D gene, c.4981del; p.(Glu1661Serfs*61), and a novel hemizygote missense variant in the KDM6A gene, c.3301G>A; p.(Glu1101Lys), were detected in patients 1 and 2, respectively. The frameshift variant identified in the first family was de novo, while in the second family, the mother was also heterozygous for the missense variant. The frameshift variant in KMT2D is predicted to lead to a truncated protein which is functionally impaired. The Glu1101 residue of KDM6A (UTX) affected in the second patient is located in a conserved region on the surface of the Jumonji domain and predicted to be causative. Our findings provide evidence on the possible pathogenicity of these 2 variants; however, additional functional studies are necessary to confirm their impacts.

Autosomal Recessive Primary Microcephaly (MCPH): An Update

2017 ◽  
Vol 48 (03) ◽  
pp. 135-142 ◽  
Author(s):  
Deborah Morris-Rosendahl ◽  
Angela Kaindl ◽  
Sami Zaqout
Keyword(s):  
Intellectual Disability ◽  
Head Circumference ◽  
Autosomal Recessive ◽  
Neurodevelopmental Disorder ◽  
Speech Disorder ◽  
Rare Disorder ◽  
Primary Microcephaly ◽  
Expressive Speech ◽  
Autosomal Recessive Primary Microcephaly

AbstractAutosomal recessive primary microcephaly (MCPH; MicroCephaly Primary Hereditary) is a genetically heterogeneous neurodevelopmental disorder characterized by a significantly reduced head circumference present already at birth and intellectual disability. Inconsistent features include hyperactivity, an expressive speech disorder, and epilepsy. Here, we provide a brief overview on this rare disorder pertinent for clinicians.

scholarly journals Turkish cases of Mabry Syndrome with a novel homozygous mutation in PGAP2 gene

2021 ◽  
Author(s):  
Ayşe Kartal ◽  
Sandeep Jaiswar
Keyword(s):  
Alkaline Phosphatase ◽  
Mental Retardation ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genetic Disorder ◽  
Missense Variant ◽  
Homozygous Mutation ◽  
Elevated Alkaline Phosphatase ◽  
Dysmorphic Features ◽  
Whole Exome

Abstract Hyperphosphatasia with mental retardation syndrome is a genetic disorder. We report two siblings aged three years and fourteen years who were investigated for global development delays, seizures and dysmorphic features. A novel missense variant, c.1003G>A (p. Ala335 Thr chr11.3,846,572 NM_001256236.1), in PGAP2 gene was identified using whole-exome sequencing. We highlight the significance of elevated alkaline phosphatase in patients with certain dysmorphic features, can lead to the diagnosis of hyperphosphatasia with mental retardation syndrome using exome sequencing.

scholarly journals A Novel Frameshift Mutation in KAT6A Is Associated with Pancraniosynostosis

2020 ◽  
Author(s):  
Fady P. Marji ◽  
Jennifer A. Hall ◽  
Erin Anstadt ◽  
Suneeta Madan-Khetarpal ◽  
Jesse A. Goldstein ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Frameshift Mutation ◽  
De Novo ◽  
Cranial Sutures ◽  
Speech Delay ◽  
First Case ◽  
Whole Exome ◽  
Suture Fusion

AbstractDe novo heterozygous mutations in the KAT6A gene give rise to a distinct intellectual disability syndrome, with features including speech delay, cardiac anomalies, craniofacial dysmorphisms, and craniosynostosis. Here, we reported a 16-year-old girl with a novel pathogenic variant of the KAT6A gene. She is the first case to possess pancraniosynostosis, a rare suture fusion pattern, affecting all her major cranial sutures. The diagnosis of KAT6A syndrome is established via recognition of its inherent phenotypic features and the utilization of whole exome sequencing. Thorough craniofacial evaluation is imperative, craniosynostosis may require operative intervention, the delay of which may be detrimental.

scholarly journals Identification of a Novel MICU1 Nonsense Variant Causes Myopathy with Extrapyramidal Signs in an Iranian Consanguineous Family

2020 ◽  
Author(s):  
Fatemeh Bitarafan ◽  
Mehrnoosh Khodaeian ◽  
Elham Amjadi Sardehaei ◽  
Fatemeh Zahra Darvishi ◽  
Navid Almadani ◽  
...  
Keyword(s):  
Cell Death ◽  
Elevated Serum ◽  
Mitochondrial Calcium ◽  
Molecular Testing ◽  
Iranian Patient ◽  
Whole Exome ◽  
Serum Creatine Phosphokinase ◽  
Extrapyramidal Signs ◽  
Hepatic Transaminase

Abstract Background: Ca2+ as a universal second messenger regulates basic biological functions including cell cycle, cell proliferation, cell differentiation and cell death. Lack of the protein mitochondrial calcium uptake1 (MICU1) which has been regarded as a gatekeeper of Ca ions, leads to the abnormal mitochondrial Ca2+ handling, excessive production of reactive oxygen species (ROS), and increased cell death. Mutations in MICU1 gene (NM_006077.3) causes a very rare neuromuscular disease, Myopathy with extrapyramidal signs (MPXPS), due to primary alterations in mitochondrial calcium signaling which demonstrates the key role of mitochondrial Ca2+ uptake. To date 6 variants have been reported in MICU1 gene in approximately 21 pedigrees.Case presentation: here we report a 44-year-old Iranian patient presented with learning disability, muscle weakness, easy fatigability, reduced tendon reflexes, ataxia, elevated hepatic transaminase, elevated serum creatine phosphokinase and gait disturbance. We Identified a novel nonsense variant c.385C>T; p.(R129*) in MICU1 gene by whole exome sequencing and segregation analysis.Conclusions: Our finding along with previous studies provides more evidence on the clinical presentation of the disease caused by pathogenic mutations in MICU1. Finding more variants and expanding the spectrum of the disease increases the diagnostic rate of molecular testing in screening of this kind of diseases and in turn improves the quality of counseling for at risk couples and helps them to minimize the risks of having affected children.

scholarly journals A Homozygous AKNA Frameshift Variant Is Associated with Microcephaly in a Pakistani Family

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1494
Author(s):  
Syeda Seema Waseem ◽  
Abubakar Moawia ◽  
Birgit Budde ◽  
Muhammad Tariq ◽  
Ayaz Khan ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Brain Size ◽  
Genetic Disorder ◽  
Normal Brain ◽  
Speech Impairment ◽  
Mild Intellectual Disability ◽  
Microtubule Organization ◽  
C Terminus ◽  
Whole Exome ◽  
Functional Features

Primary microcephaly (MCPH) is a prenatal condition of small brain size with a varying degree of intellectual disability. It is a heterogeneous genetic disorder with 28 associated genes reported so far. Most of these genes encode centrosomal proteins. Recently, AKNA was recognized as a novel centrosomal protein that regulates neurogenesis via microtubule organization, making AKNA a likely candidate gene for MCPH. Using linkage analysis and whole-exome sequencing, we found a frameshift variant in exon 12 of AKNA (NM_030767.4: c.2737delG) that cosegregates with microcephaly, mild intellectual disability and speech impairment in a consanguineous family from Pakistan. This variant is predicted to result in a protein with a truncated C-terminus (p.(Glu913Argfs*42)), which has been shown to be indispensable to AKNA’s localization to the centrosome and a normal brain development. Moreover, the amino acid sequence is altered from the beginning of the second of the two PEST domains, which are rich in proline (P), glutamic acid (E), serine (S), and threonine (T) and common to rapidly degraded proteins. An impaired function of the PEST domains may affect the intracellular half-life of the protein. Our genetic findings compellingly substantiate the predicted candidacy, based on its newly ascribed functional features, of the multifaceted protein AKNA for association with MCPH.

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