Somatic and germline mosaic mutations in the doublecortin gene are associated with variable phenotypes.
Mutations in the X-linked gene doublecortin lead to "double cortex" syndrome (DC) in females and to X-linked lissencephaly (XLIS) in males. Because most patients with DC and XLIS are sporadic, representing de novo doublecortin mutations, we considered that some of these patients could be somatic or germline mosaics. Among a population of 20 patients and their families, we found evidence for mosaic doublecortin mutations in 6 individuals. Germline mosaicism was identified in two unaffected women, each with two affected children. Additionally, one affected male with DC was found to be a somatic mosaic, which presumably spared him from the more severe phenotype of lissencephaly. The high rate of mosaicism indicates that there may be a significant recurrence risk for DC/XLIS in families at risk, even when the mother is unaffected.
Division of Pediatric Neurology, Department of Neurosciences, University of California at San Diego, La Jolla, CA, 92093, USA. jogleeson@ucsd.edu
J G
JG
Gleeson
S
S
Minnerath
R I
RI
Kuzniecky
W B
WB
Dobyns
I D
ID
Young
M E
ME
Ross
C A
CA
Walsh
D000328:Adult; D001483:Base Sequence; D001921:Brain / Q000002:abnormalities* / Q000378:metabolism; D002648:Child; D004252:DNA Mutational Analysis; D000089622:Doublecortin Domain Proteins; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018095:Germ-Line Mutation / Q000235:genetics*; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008869:Microtubule-Associated Proteins; D009030:Mosaicism / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D009479:Neuropeptides / Q000235:genetics*; D009679:Nuclear Family; D010375:Pedigree; D010641:Phenotype; D013577:Syndrome
D000089622:Doublecortin Domain Proteins; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides