Autosomal Recessive Primary Microcephaly Research Articles

Loss of abnormal spindle-like, microcephaly-associated (Aspm) disrupts female folliculogenesis in mice during maturation and aging

The abnormal spindle-like, microcephaly-associated (ASPM) gene is a causative gene of autosomal recessive primary microcephaly (MCPH) 5 in humans, which is characterized by a reduction in brain volume. It was previously reported that truncated Aspm proteins in transgenic mice caused major defects in the germline, a severe reduction in ovary weight and the number of follicles accompanied by reduced fertility. However; it remains unknown whether a loss of Aspm induces abnormal ovarian function, resulting in female infertility. In order to assess the ovary function, we examined vaginal smear cytology from the age of 7 weeks to 100 weeks in CAG-mediated Cre-loxP conditional Aspm-/- knockout mice and control female mice. In addition, we evaluated the ovarian size, fibrosis ratio and the number of follicles (primordial, primary, secondary, antral and atretic follicles) in mice from 15 weeks to 100 weeks old by image analyses. Mann-Whitney U-test was used for statistical analysis. The size of the ovary was significantly reduced in Aspm knockout mice at 15–20 weeks, 40–50 weeks and 70–80 weeks old compared with the control mice. Furthermore, at all stages, we found a severe decrease in the number of developing follicles at 10–15 weeks, 40–50 weeks and 70–80 weeks old, accompanied by disrupted cyclic changes of vaginal cytology and an aberrant upregulation of Foxo3, Kitl, and Lhcgr in Aspm knockout female. These results suggested that Aspm might play an important role in the folliculogenesis and estrous cyclicity of the postnatal ovary during maturation and aging.

Autosomal Recessive Primary Microcephaly (MCPH) and Novel Pathogenic Variants in ASPM and WDR62 Genes

Introduction: Autosomal recessive primary microcephaly (MCPH) is a disorder characterized by congenital microcephaly and intellectual disability without extra-central nervous system malformation. MCPH is a disease with heterogeneity in genotype and phenotype. For this reason, it is important to determine the genetic causes and genotype-phenotype relationship in MCPH, which causes lifelong impairment. In this study, we aimed to evaluate the clinical, genetic, and brain imaging findings of cases diagnosed with MCPH. Methods: Electroencephalogram and brain magnetic resonance imaging were performed for all cases. We evaluated genetic results of the 39 families including cases with suspected MCPH diagnosis. Results: Genetic diagnosis related to MCPH was provided in 11/39 (28.2%) of these families including 13/41 cases (31.7%). Variants of the WDR62 gene were the most common (61.5%) cause, and variants of the ASPM gene were the second most common cause (38.5%). We have found 6 novel variants and 4 previously reported variants in ASPM and WDR62 genes. Main brain imaging findings in our cases were lissencephaly, polymicrogyria, schizencephaly, pachygyria, and cortical dysplasia. Genetic counseling in 2 families whose genetic diagnosis was determined prevented them from having another child with MCPH. Discussion/Conclusion: Detection and reporting of novel variants is an important step in eliminating this disorder by providing families with appropriate genetic counseling.

Diagnosis and counseling for a Chinese pedigree affected with autosomal recessive primary microcephaly 5 due to variants of ASPM gene

To detect potential mutation of the ASPM gene in a Chinese pedigree affected with autosomal recessive primary microcephaly 5 (MCPH5). Peripheral venous blood samples were collected from the proband and her parents. Amniotic fluid sample was also collected upon her mother' s subsequent pregnancy. Following extraction of genomic DNA, PCR and Sanger sequencing were carried out to identify potential variants of the ASPM gene. The proband was found to harbor compound heterozygous variants of the ASPM gene, namely c.8214dupT (p.Q2739fs) in exon 18 and c.9541C>T (p.R3181X) in exon 23, which were respectively inherited from her father and mother. The fetus has found to have inherited the c.9541C>T (p.R3181X) variant only. The c.8214dupT (p.Q2739fs) and c.9541C>T (p.R3181X) compound heterozygous variants of the ASPM gene probably underlay the pathogenesis of MCPH5 in this patient. Above finding has enabled genetic counseling and prenatal diagnosis for her family.

Expression Analyses of Cep152, a Responsible Gene Product for Autosomal Recessive Primary Microcephaly, during Mouse Brain Development

Centrosomal protein 152 (Cep152) regulates centriole duplication as a molecular scaffold during the cell cycle. Its gene abnormalities are responsible for autosomal recessive primary microcephaly 9 and Seckel syndrome. In this study, we prepared an antibody against mouse Cep152, anti-Cep152, and performed expression analyses focusing on mouse brain development. Western blotting analyses revealed that Cep152 with a molecular mass of ∼150 kDa was expressed strongly at embryonic day (E)13 and then gradually decreased during the brain development process. Instead, protein bands of ∼80 kDa and ∼60 kDa came to be recognized after postnatal day (P)15 and P30, respectively. In immunohistochemical analyses, Cep152 was enriched in the centrosome of neuronal progenitors in the ventricular zone at E14, whereas it was diffusely distributed mainly in the cytoplasm of cortical neurons at P18. In developing cerebellum at P7, Cep152 was localized at the centrosome in the external granular layer, where neurogenesis takes place. Notably, biochemical analysis revealed that Cep152 was also present in the postsynaptic density fraction. Subsequent immunofluorescent analyses showed co-localization of Cep152 with excitatory synaptic markers, PSD95 and synaptophysin, but not with an inhibitory synaptic marker gephyrin in differentiated primary cultured hippocampal neurons. The obtained results suggest that Cep152 takes part not only in neurogenesis during corticogenesis but also in the regulation of synaptic function in differentiated neurons.

Modeling Human Primary Microcephaly With hiPSC-Derived Brain Organoids Carrying CPAP-E1235V Disease-Associated Mutant Protein.

The centrosome is composed of a pair of centrioles and serves as the major microtubule-organizing center (MTOC) in cells. Centrosome dysfunction has been linked to autosomal recessive primary microcephaly (MCPH), which is a rare human neurodevelopmental disorder characterized by small brain size with intellectual disability. Recently, several mouse models carrying mutated genes encoding centrosomal proteins have been generated to address the genotype–phenotype relationships in MCPH. However, several human-specific features were not observed in the mouse models during brain development. Herein, we generated isogenic hiPSCs carrying the gene encoding centrosomal CPAP-E1235V mutant protein using the CRISPR-Cas9 genome editing system, and examined the phenotypic features of wild-type and mutant hiPSCs and their derived brain organoids. Our results showed that the CPAP-E1235V mutant perturbed the recruitment of several centriolar proteins involved in centriole elongation, including CEP120, CEP295, CENTROBIN, POC5, and POC1B, onto nascent centrioles, resulting in the production of short centrioles but long cilia. Importantly, our wild-type hiPSC-derived brain organoid recapitulated many cellular events seen in the developing human brain, including neuronal differentiation and cortical spatial lamination. Interestingly, hiPSC-CPAP-E1235V-derived brain organoids induced p53-dependent neuronal cell death, resulting in the production of smaller brain organoids that mimic the microcephaly phenotype. Furthermore, we observed that the CPAP-E1235V mutation altered the spindle orientation of neuronal progenitor cells and induced premature neuronal differentiation. In summary, we have shown that the hiPSC-derived brain organoid coupled with CRISPR/Cas9 gene editing technology can recapitulate the centrosome/centriole-associated MCPH pathological features. Possible mechanisms for MCPH with centriole/centrosome dysfunction are discussed.

Autosomal Recessive Primary Microcephaly: Not Just a Small Brain.

Microcephaly or reduced head circumference results from a multitude of abnormal developmental processes affecting brain growth and/or leading to brain atrophy. Autosomal recessive primary microcephaly (MCPH) is the prototype of isolated primary (congenital) microcephaly, affecting predominantly the cerebral cortex. For MCPH, an accelerating number of mutated genes emerge annually, and they are involved in crucial steps of neurogenesis. In this review article, we provide a deeper look into the microcephalic MCPH brain. We explore cytoarchitecture focusing on the cerebral cortex and discuss diverse processes occurring at the level of neural progenitors, early generated and mature neurons, and glial cells. We aim to thereby give an overview of current knowledge in MCPH phenotype and normal brain growth.

A Two-Base Pair Deletion in IQ Repeats in ASPM Underlies Microcephaly in a Pakistani Family.

Aims: Autosomal recessive primary microcephaly (MCPH) is a clinically rare and genetically highly heterogeneous developmental disorder. Biallelic variants in the abnormal spindle-like microcephaly-associated (ASPM) gene account for 40% to 68% of all MCPH cases. This study was designed to elucidate the genetic basis of MCPH in an extended family. To highlight recurrent mutations useful in implementing genetic testing programs, we further aimed to carry out a descriptive review of the reported ASPM mutations. Materials and Methods: A large inbred kindred with seven affected members was investigated, and detailed clinical and behavioral assessments were carried out. Single nucleotide polymorphism (SNP)-based homozygosity mapping and exome sequencing were performed. Results: Affected individuals had characteristic features, including small head, receding forehead, mild to moderate intellectual disability, developmental delay, short stature, apraxia, and behavioral anomalies. We mapped the disease gene locus and detected a rare frameshift deletion c.6854_6855del (p.(Leu2285GlnfsTer32)) in exon 18 of ASPM. A total of 215 mutations in ASPM have been reported in at least 453 families, nearly 50% of which are of Pakistani origin. These mutations can be classified as recurrent, founder or private in Pakistani and other populations. Conclusion: SNP-based homozygosity mapping and exome sequencing are essential in delineating the genetically distinct microcephaly types. The highlighted recurrent mutations in ASPM could be useful in implementing genetic testing programs for MCPH.

A Missense Variant in LAMA3 Gene Causes Microcephaly and Epidermolysis Bullosa in a Pakistani Family

OBJECTIVE: To identify the disease-causing mutation in a family with autosomal recessive primarymicrocephaly (MCPH).METHODOLOGY: This cross-sectional study was the continuation of an ongoing family-based studyinitiated in 2016 at the Department of Biochemistry, Quaid-e-Azam University, Islamabad. The family wasselected randomly and recruited from Sahiwal and has three members with MCPH. DNA was isolatedfrom blood samples and the genome-wide scan was performed to map homozygous regions. Wholeexome sequencing (WES) was performed to identify the plausible gene variant.RESULTS: Whole genome data analysis identified multiple homozygous regions, but none of thesecontain known MCPH genes. Whole exome sequencing (WES) data identified six potentially pathogenic variants but only the Laminin subunit alpha-3 (LAMA3) (c.5260C/T) variant segregates in the family andis also present within the genomic region mapped on chromosome 18. The reevaluation of affectedmembers of the family revealed the presence of blisters on their hands and feet indicating the presenceof epidermolysis bullosa along with microcephaly.CONCLUSION: The casual finding of the LAMA3 variant (c.5260C/T; p. Arg1754Trp) and absence of anyother MCPH causing variant in affected members of this family expands the phenotypic spectrum ofLAMA3 associated phenotype. Therefore, we can conclude that the LAMA3 variant can probably causerecessive microcephaly and epidermolysis bullosa, but additional studies are needed to establish therole of LAMA3 in microcephaly. KEY WORDS: MCPH, LAMA3, Laminin-5, Genome scan, homozygous regions, whole-exome sequencing.

The Role of Mfsd2a in Nervous System Diseases.

Major facilitator superfamily (MFS) is the maximum and most diversified membrane transporter, acting as uniporters, symporters and antiporters. MFS is considered to have a good development potential in the transport of drugs for the treatment of brain diseases. The major facilitator superfamily domain containing protein 2a (Mfsd2a) is a member of MFS. Mfsd2a-knockout mice have shown a marked decrease of docosahexaenoic acid (DHA) level in brain, exhibiting neuron loss, microcephaly and cognitive deficits, as DHA acts essentially in brain growth and integrity. Mfsd2a has attracted more and more attention in the study of nervous system diseases because of its critical role in maintaining the integrity of the blood-brain barrier (BBB) and transporting DHA, including inhibiting cell transport in central nervous system endothelial cells, alleviating BBB injury, avoiding BBB injury in cerebral hemorrhage model, acting as a carrier etc. Up to now, the clinical research of Mfsd2a in nervous system diseases is rare. This article reviewed the current research progress of Mfsd2a in nervous system diseases. It summarized the physiological functions of Mfsd2a in the occurrence and development of intracranial hemorrhage (ICH), Alzheimer’s disease (AD), sepsis-associated encephalopathy (SAE), autosomal recessive primary microcephaly (MCPH) and intracranial tumor, aiming to provide ideas for the basic research and clinical application of Mfsd2a.

MFSD2A-associated primary microcephaly - Expanding the clinical and mutational spectrum of this ultra-rare disease

MFSD2A, a member of the major facilitator superfamily (MFS), is a transmembrane transporter responsible for the uptake of specific essential fatty acids through the blood-brain barrier (BBB) to the brain. The transporter is crucial for early embryonic brain development and a major factor in the formation and maintenance of the BBB. Mfsd2a-knockout mice show a leakage of the BBB in early embryonic stages and develop a phenotype characterized by microcephaly, cognitive impairment, and anxiety. So far, homozygous or compound heterozygous MFSD2A mutations in humans have only been reported in 13 different families with a total of 28 affected individuals. The phenotypical spectrum of patients with MFSD2A variants is rather broad but all patients present with microcephaly and severe intellectual disability, absent or limited speech, and walking difficulties. Severely affected patients develop seizures and show brain malformations and have, above all, a profound developmental delay hardly reaching any developmental motor milestones. Here, we report on two unrelated individuals with novel homozygous variants in the MFSD2A gene, presenting with severe primary microcephaly, brain malformations, profound developmental delay, and epilepsy, including hypsarrhythmia.Our findings extend the mutational spectrum of the bi-allelic MFSD2A variants causing autosomal recessive primary microcephaly type 15 and broaden the phenotypic spectrum associated with these pathogenic variants emphasizing the role of MFSD2A in early brain development.

Updates on Clinical and Genetic Heterogeneity of ASPM in 12 Autosomal Recessive Primary Microcephaly Families in Pakistani Population.

Microcephaly (MCPH) is a genetically heterogeneous disorder characterized by non-progressive intellectual disability, small head circumference, and small brain size compared with the age- and sex-matched population. MCPH manifests as an isolated condition or part of another clinical syndrome; so far, 25 genes have been linked with MCPH. Many of these genes are reported in Pakistani population, but due to a high rate of consanguinity, a significant proportion of MCPH cohort is yet to be explored. MCPH5 is the most frequently reported type, accounting for up to 68.75% alone in a genetically constrained population like Pakistan. In the current study, whole exome sequencing (WES) was performed on probands from 10 families sampled from South Waziristan and two families from rural areas of the Pakistani Punjab. Candidate variants were validated through Sanger sequencing in all available family members. Variant filtering and in silico analysis identified three known mutations in ASPM, a MCPH5-associated gene. The founder mutation p.Trp1326* was segregating in 10 families, which further confirmed the evidence that it is the most prominent mutation in Pashtun ethnicity living in Pakistan and Afghanistan. Furthermore, the previously known mutations p.Arg3244* and p.Arg1019* were inherited in two families with Punjab ethnic profile. Collectively, this study added 12 more families to the mutational paradigm of ASPM and expanded the Pakistani MCPH cohort.

Human Microcephaly Protein RTTN Is Required for Proper Mitotic Progression and Correct Spindle Position.

Autosomal recessive primary microcephaly (MCPH) is a complex neurodevelopmental disorder characterized by a small brain size with mild to moderate intellectual disability. We previously demonstrated that human microcephaly RTTN played an important role in regulating centriole duplication during interphase, but the role of RTTN in mitosis is not fully understood. Here, we show that RTTN is required for normal mitotic progression and correct spindle position. The depletion of RTTN induces the dispersion of the pericentriolar protein γ-tubulin and multiple mitotic abnormalities, including monopolar, abnormal bipolar, and multipolar spindles. Importantly, the loss of RTTN altered NuMA/p150Glued congression to the spindle poles, perturbed NuMA cortical localization, and reduced the number and the length of astral microtubules. Together, our results provide a new insight into how RTTN functions in mitosis.

Homozygous mutation in MCM7 causes autosomal recessive primary microcephaly and intellectual disability

BackgroundMinichromosomal maintenance (MCM) complex components 2, 4, 5 and 6 have been linked to human disease with phenotypes including microcephaly and intellectual disability. The MCM complex has DNA helicase activity...

Molecular evolutionary analysis of human primary microcephaly genes

BackgroundThere has been a rapid increase in the brain size relative to body size during mammalian evolutionary history. In particular, the enlarged and globular brain is the most distinctive anatomical feature of modern humans that set us apart from other extinct and extant primate species. Genetic basis of large brain size in modern humans has largely remained enigmatic. Genes associated with the pathological reduction of brain size (primary microcephaly-MCPH) have the characteristics and functions to be considered ideal candidates to unravel the genetic basis of evolutionary enlargement of human brain size. For instance, the brain size of microcephaly patients is similar to the brain size of Pan troglodyte and the very early hominids like the Sahelanthropus tchadensis and Australopithecus afarensis.ResultsThe present study investigates the molecular evolutionary history of subset of autosomal recessive primary microcephaly (MCPH) genes; CEP135, ZNF335, PHC1, SASS6, CDK6, MFSD2A, CIT, and KIF14 across 48 mammalian species. Codon based substitutions site analysis indicated that ZNF335, SASS6, CIT, and KIF14 have experienced positive selection in eutherian evolutionary history. Estimation of divergent selection pressure revealed that almost all of the MCPH genes analyzed in the present study have maintained their functions throughout the history of placental mammals. Contrary to our expectations, human-specific adoptive evolution was not detected for any of the MCPH genes analyzed in the present study.ConclusionBased on these data it can be inferred that protein-coding sequence of MCPH genes might not be the sole determinant of increase in relative brain size during primate evolutionary history.

Novel variant in BRAT1 with the lethal neonatal rigidity and multifocal seizure syndrome.

Lethal neonatal rigidity and multifocal seizure syndrome (RMFSL) is caused by variants in BRAT1 (BRCA1-associated protein required for ATM activation-1). However, the molecular mechanism of RMFSL is still unclear. An RMFSL infant was recruited and the peripheral blood samples from his trio-family were collected. The genomic DNA was extracted, and then the whole-exome sequencing was performed. The expression of BRAT1 was analyzed by Western blotting. The subcellular localization of BRAT1 and MitoSOX (mitochondrial superoxide level) was investigated by confocal microscopy. The RNA samples were obtained from transfected cells, and then the RNA sequencing was performed. In this study, a novel homozygous BRAT1 variant c.233G > C with amino acid change of R with P at residue 78 (R78P) was identified. This variant altered the peptide structure and subcellular localization, as well as the expression in vitro. However, R78P did not alter the ability of BRAT1 to downregulate MitoSOX in mitochondria. Meanwhile, R78P BRAT1 was positively correlated with temporal lobe epilepsy, autosomal recessive primary microcephaly, defective/absent horizontal voluntary eye movements, and neuron apoptotic process as indicated by gene set enrichment analysis (GSEA). The BRAT1 variant spectrum has been expanded, which will be helpful for genetic counseling. We also explored the molecular mechanism altered by R78P, which will provide a better understanding of the pathogenesis of RMFSL. The detailed course of an infant with lethal neonatal RMFSL was depicted. A novel disease-causing variant R78P in BRAT1 for lethal neonatal RMFSL was identified. R78P led to reduced BRAT1 expression and nuclear localization in vitro. R78P did not alter the ability of BRAT1 to downregulate MitoSOX in the mitochondria. The variant R78P in BRAT1 was positively correlated with temporal lobe epilepsy, autosomal recessive primary microcephaly, defective/absent horizontal voluntary eye movements, and neuron apoptotic process as indicated by GSEA.

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

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.

Structure and Function of Abnormal Spindle-Like, Microtubule Associated Protein (ASPM)

Human autosomal recessive primary microcephaly (MCPH) is a hereditary disorder associated with a small brain and associated intellectual disability. Mutations in the gene for Abnormal Spindle-like, Microtubule Associated protein (ASPM) are the most common causes of MCPH. ASPM, a large (∼400kDa) protein, is important in mitosis. It anchors the mitotic spindle at the spindle poles and is essential for normal cytokinesis. However, the complete structure-function of ASPM is not well understood.The N-terminal domain of ASPM contains 2 tandem calponin homology (CH) domains and binds microtubules. However the location of the specific binding site is unclear. Two tandem CH domains typically bind actin, whereas single CH domains bind microtubules suggesting the CH domains of ASPM bind actin. The region following the CH domains contains 81 isoleucine-glutamine (IQ) motifs, known to bind light chains such as calmodulin. These motifs form a single alpha-helix to which the light chains bine, suggesting an overall elongated structure for ASPM.Using a combination of mass spectrometry and flow cell assays, we determined that the tandem CH domains of ASPM bind to microtubules, and not actin, suggesting that the CH domains may be the key binding site of ASPM for microtubules within the N-terminus. Negative stain electron microscopy of a central 21 IQ motif-containing domain revealed a long semi-flexible molecule, fully decorated with light chains. These data thus start to reveal the structure and function of ASPM.

Expanding the phenotype of NUP85 mutations beyond nephrotic syndrome to primary autosomal recessive microcephaly and Seckel syndrome spectrum disorders.

Primary autosomal recessive microcephaly and Seckel syndrome spectrum disorders (MCPH-SCKS) include a heterogeneous group of autosomal recessive inherited diseases characterized by primary (congenital) microcephaly, the absence of visceral abnormalities, and a variable degree of cognitive impairment, short stature and facial dysmorphism. Recently, biallelic variants in the nuclear pore complex (NPC) component nucleoporin 85 gene (NUP85) were reported to cause steroid-resistant nephrotic syndrome (SRNS). Here, we report biallelic variants in NUP85 in two pedigrees with an MCPH-SCKS phenotype spectrum without SRNS, thereby expanding the phenotypic spectrum of NUP85-linked diseases. Structural analysis predicts the identified NUP85 variants cause conformational changes that could have an effect on NPC architecture or on its interaction with other NUPs. We show that mutant NUP85 is, however, associated with a reduced number of NPCs but unaltered nucleocytoplasmic compartmentalization, abnormal mitotic spindle morphology, and decreased cell viability and proliferation in one patient's cells. Our results also indicate the link of common cellular mechanisms involved in MCPH-SCKS spectrum disorders and NUP85-associated diseases. In addition to the previous studies, our results broaden the phenotypic spectrum of NUP85-linked human disease and propose a role for NUP85 in nervous system development.

Clinical and genetic characteristics of 2 patients from Russia with autosomal-recessive microcephaly type 2, due to mutations of the WDR62 gene (OMIM: 604317)

The article describes the clinical and genetic characteristics of 2 patients from Russia with autosomal recessive primary microcephaly type 2, caused by previously described and newly identified mutations in the WDR62 gene. The data obtained the support the hypothesis that there are no clear correlations between the type and location of the mutation and the severity of clinical manifestations of the disease. There is discussed the possible influence of a mutation in the WDR62 gene on the occurrence of a fibrillar astrocytoma.

Generation of a MCPH1 knockout human embryonic stem cell line by CRISPR/Cas9 technology.

Human MCPH1 (Microcephalin 1) encodes a DNA damage response protein. Mutations in this gene have been associated with Primary Autosomal Recessive Microcephaly and premature chromosome condensation syndrome. To further understand the roles of MCPH1 in neural differentiation and brain development, here we generated a MCPH1 knockout human embryonic stem cell line by CRISPR/Cas9 genome editing technology. This cell line maintained a normal karyotype and typical undifferentiated state in terms of morphology, pluripotent gene expression, and had differentiation potential in vitro. This cell line provides a good resource to study the role of MCPH1 gene in neurogenesis and regulation of the size of the cerebral cortex in vitro.