Deletion of MAOA and MAOB in a male patient causes severe developmental delay, intermittent hypotonia and stereotypical hand movements.
Monoamine oxidases (MAO-A and MAO-B) have a key role in the degradation of amine neurotransmitters, such as dopamine, norepinephrine and serotonin. We identified an inherited 240 kb deletion on Xp11.3-p11.4, which encompasses both monoamine oxidase genes but, unlike other published reports, does not affect the adjacent Norrie disease gene (NDP). The brothers who inherited the deletion, and thus have no monoamine oxidase function, presented with severe developmental delay, intermittent hypotonia and stereotypical hand movements. The clinical features accord with published reports of larger microdeletions and selective MAO-A and MAO-B deficiencies in humans and mouse models and suggest considerable functional compensation between MAO-A and MAO-B under normal conditions.
Whibley
Annabel
A
Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
Urquhart
Jill
J
Dore
Jonathan
J
Willatt
Lionel
L
Parkin
Georgina
G
Gaunt
Lorraine
L
Black
Graeme
G
Donnai
Dian
D
Raymond
F Lucy
FL
D041321:Chromosomes, Human, X / Q000235:genetics / Q000648:ultrastructure; D002658:Developmental Disabilities / Q000235:genetics*; D020820:Dyskinesias / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D008995:Monoamine Oxidase / Q000172:deficiency* / Q000235:genetics*; D009123:Muscle Hypotonia / Q000235:genetics; D016133:Polymerase Chain Reaction; D013239:Stereotyped Behavior
D008995:Monoamine Oxidase