A 15q13.3 homozygous microdeletion associated with a severe neurodevelopmental disorder suggests putative functions of the TRPM1, CHRNA7, and other homozygously deleted genes.
We identified a novel homozygous 15q13.3 microdeletion in a young boy with a complex neurodevelopmental disorder characterized by severe visual impairment, hypotonia, profound intellectual disability, and refractory epilepsy. The homozygous deletion of the genes within this deleted region provides a useful insight into the pathogenesis of the observed clinical phenotype. Absence of the Transient Receptor Potential Cation Channel, Subfamily M, Member 1 (TRPM1) gene product is proposed as a possible mechanism for the severe visual impairment; absence of CHRNA7 (alpha7-nicotinic receptor subunit) as a cause of the refractory seizures and severe cognitive impairment; and deletion of MTMR10 and/or MTMR15 (encoding myotubularin related proteins) alone or combined with other homozygously deleted genes as a cause for the congenital hypotonia with areflexia. The distinctive clinical findings in this patient reveal potential functions of the genes within the deleted region.
Lepichon
Jean-Baptiste
JB
Section of Neurology, Children's Mercy Hospitals and Clinics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.
Bittel
Douglas C
DC
Graf
William D
WD
Yu
Shihui
S
D002648:Child; D002872:Chromosome Deletion; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D002658:Developmental Disabilities / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007223:Infant; D008297:Male; D011978:Receptors, Nicotinic / Q000235:genetics*; D050053:TRPM Cation Channels / Q000235:genetics*; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579167:Chrna7 protein, human; D011978:Receptors, Nicotinic; D050053:TRPM Cation Channels; C492059:TRPM1 protein, human; D064569:alpha7 Nicotinic Acetylcholine Receptor