In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 109, No. 21 ( 2012-05-22), p. 7974-7981
Abstract:
We recently reported a deletion of exon 2 of the trimethyllysine hydroxylase epsilon ( TMLHE ) gene in a proband with autism. TMLHE maps to the X chromosome and encodes the first enzyme in carnitine biosynthesis, 6- N -trimethyllysine dioxygenase. Deletion of exon 2 of TMLHE causes enzyme deficiency, resulting in increased substrate concentration (6- N -trimethyllysine) and decreased product levels (3-hydroxy-6- N -trimethyllysine and γ-butyrobetaine) in plasma and urine. TMLHE deficiency is common in control males (24 in 8,787 or 1 in 366) and was not significantly increased in frequency in probands from simplex autism families (9 in 2,904 or 1 in 323). However, it was 2.82-fold more frequent in probands from male-male multiplex autism families compared with controls (7 in 909 or 1 in 130; P = 0.023). Additionally, six of seven autistic male siblings of probands in male-male multiplex families had the deletion, suggesting that TMLHE deficiency is a risk factor for autism (metaanalysis Z-score = 2.90 and P = 0.0037), although with low penetrance (2–4%). These data suggest that dysregulation of carnitine metabolism may be important in nondysmorphic autism; that abnormalities of carnitine intake, loss, transport, or synthesis may be important in a larger fraction of nondysmorphic autism cases; and that the carnitine pathway may provide a novel target for therapy or prevention of autism.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1120210109
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2012
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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