New SMS mutation leads to a striking reduction in spermine synthase protein function and a severe form of Snyder-Robinson X-linked recessive mental retardation syndrome.
We report the identification of a novel mutation at a highly conserved residue within the N-terminal region of spermine synthase (SMS) in a second family with Snyder-Robinson X-linked mental retardation syndrome (OMIM 309583). This missense mutation, p.G56S, greatly reduces SMS activity and leads to severe epilepsy and cognitive impairment. Our findings contribute to a better delineation and expansion of the clinical spectrum of Snyder-Robinson syndrome, support the important role of the N-terminus in the function of the SMS protein, and provide further evidence for the importance of SMS activity in the development of intellectual processing and other aspects of human development.
de Alencastro
G
G
McCloskey
D E
DE
Kliemann
S E
SE
Maranduba
C M C
CM
Pegg
A E
AE
Wang
X
X
Bertola
D R
DR
Schwartz
C E
CE
Passos-Bueno
M R
MR
Sertié
A L
AL
D000328:Adult; D002648:Child; D004252:DNA Mutational Analysis; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D008297:Male; D038901:X-Linked Intellectual Disability / Q000235:genetics*; D020125:Mutation, Missense; D010375:Pedigree; D013097:Spermine Synthase / Q000235:genetics*; D013577:Syndrome
D013097:Spermine Synthase