Journal Article

Genomic and phenotypic delineation of congenital microcephaly

Abdulwahab, Firdous, Al-Owain, Mohammed, Maddirevula, Sateesh, Alkhalifi, Salwa, Aglan, Mona, Shaheen, Ranad, Patel, Nisha, Partlow, Jennifer N., Alobeid, Eman, Fregeau, Brieana, Tulbah, Maha, Tala, Saeed Al, Momin, Afaque A., Şahintürk, Serdar, Sherr, Elliott, Ewida, Nour, Kentab, Amal, Alhazzani, Fahad, Saffar, Muna Al, Arold, Stefan T., Alshahwan, Saad Ali M., Abouelhoda, Mohamed, Tabarki, Brahim, Alsahli, Saud, Seidahmed, Mohammed Zain, Temtamy, Samia, Sogati, Samira, Abdel-Salam, Ghada M. H., Alhashem, Amal, Bashiri, Fahad A., Otaify, Ghada, Al-Sheddi, Tarfa, Alwadei, Ali H., Alhumaidi, Zainab, Salih, Mustafa A., Alkuraya, Fowzan S., Hashem, Mais, Abadel, Basma, Girisha, Katta M., Hamad, Muddathir, Alazami, Anas M., Walsh, Christopher, Softah, Ameen, Alomar, Rana, Ibrahim, Niema, Faqeih, Eissa, Zaki, Maha S.

2019

Overview

Purpose Congenital microcephaly (CM) is an important birth defect with long term neurological sequelae. We aimed to perform detailed phenotypic and genomic analysis of patients with Mendelian forms of CM. Methods Clinical phenotyping, targeted or exome sequencing, and autozygome analysis. Results We describe 150 patients (104 families) with 56 Mendelian forms of CM. Our data show little overlap with the genetic causes of postnatal microcephaly. We also show that a broad definition of primary microcephaly —as an autosomal recessive form of nonsyndromic CM with severe postnatal deceleration of occipitofrontal circumference—is highly sensitive but has a limited specificity. In addition, we expand the overlap between primary microcephaly and microcephalic primordial dwarfism both clinically (short stature in >52% of patients with primary microcephaly) and molecularly (e.g., we report the first instance of CEP135 -related microcephalic primordial dwarfism). We expand the allelic and locus heterogeneity of CM by reporting 37 novel likely disease-causing variants in 27 disease genes, confirming the candidacy of ANKLE2, YARS , FRMD4A , and THG1L , and proposing the candidacy of BPTF , MAP1B , CCNH , and PPFIBP1 . Conclusion Our study refines the phenotype of CM, expands its genetics heterogeneity, and informs the workup of children born with this developmental brain defect.

• Publisher: Nature Publishing Group US,Elsevier Limited
• Subject: Adult / Biomedical and Life Sciences / Biomedicine / Child / Child, Preschool / Congenital diseases / Dwarfism / Dwarfism - genetics / Exome Sequencing - methods / Female / Genomics - methods / Genotype / Human Genetics / Humans / Infant / Infant, Newborn / Laboratory Medicine / Male / Microcephaly / Microcephaly - genetics / Microcephaly - physiopathology / Mutation - genetics / Pedigree / Phenotype