Expanding the phenotype of phospholipid remodelling disease due to MBOAT7 gene defect.

ABSTRACT

MBOAT7 gene codes O-acyltransferase domain containing seven proteins which is one of four enzymes involved in remodeling of phosphoinositol phosphate (PIP) in LANDs cycle. We present clinical, neuroimaging, and genetic findings of 12 patients from 7 families with MBOAT7 gene defect, a recently defined novel phospholipid remodelling disease. To the best of our knowledge, our case series is the second report on patients with MBOAT7 gene defect. The patients present with global developmental delay particularly in speech and language skills, intellectual disability, stereotypical behavior, ataxic gait, early onset epilepsy with well response to medical treatment, strabismus and similar facial features. Common neuroimaging findings of the patients were folium dysgenesis of the cerebellum with a particular appearance, mild-to-moderate cerebellar atrophy, T2 hyperintensity of bilateral globus pallidius and dentate nuclei, enlarged perivascular areas, and mild thinning of the corpus callosum. Genome-wide genotyping and exome sequencing identified five different types of homozygous mutations in the MBOAT7 gene in all seven families which are p.Arg87*, p.Leu227ProfsX65, p.Gln376Lys, p.Trp426*, and chr1954.666.173-54.677.766/11594 bp del. We conclude that clinical and neuroimaging findings of MBOAT7 gene defect may suggest the diagnosis and guide genetic tests.