Mutations in SPATA5 Are Associated with Microcephaly, Intellectual Disability, Seizures, and Hearing Loss

Abstract

Using whole-exome sequencing, we have identified in ten families 14 individuals with microcephaly, developmental delay, intellectual disability, hypotonia, spasticity, seizures, sensorineural hearing loss, cortical visual impairment, and rare autosomal-recessive predicted pathogenic variants in spermatogenesis-associated protein 5 (SPATA5). SPATA5 encodes a ubiquitously expressed member of the ATPase associated with diverse activities (AAA) protein family and is involved in mitochondrial morphogenesis during early spermatogenesis. It might also play a role in post-translational modification during cell differentiation in neuronal development. Mutations in SPATA5 might affect brain development and function, resulting in microcephaly, developmental delay, and intellectual disability.

Figure 1

Variants in SPATA5 (A) Diagram of SPATA5 with variants identified in green. Missense and in-frame deletions are shown below, and gene-disrupting variants are shown above. (B) Sequence alignment of the CDC48 N-terminal domain (turquoise), AAA domains (yellow), and Walker A, Walker B, and second region of homology (SRH) motifs (blue text, underlined). A putative mitochondria-targeting sequence is highlighted in green, and potential ubiquitination sites are in gray. Residues altered in (A) are shown in bold red text. Species abbreviations are as follows: chimpanzee (Pantr, Pan troglodytes), fruit fly (Drome, Drosophila melanogaster), nematode (Cael, C. elegans), and budding yeast (Yeast, S. cerevisiae).