Neural tube defects and the 13q deletion syndrome: evidence for a critical region in 13q33-34.
Neural tube defects (NTD) are common findings in the 13q deletion syndrome, but the relationship between the 13q- syndrome and NTDs is poorly understood. We present a child with a 13q deletion and lumbosacral myelomeningocele. This was a boy with microcephaly, telecanthus, minor facial anomalies, and ambiguous genitalia. Cytogenetic and fluorescence in situ hybridization analysis showed a de novo 46,XY,del(13)(q33.2-->qter) with no visible translocation. By using microsatellite markers, the deletion breakpoint was mapped to a 350-kb region between D13S274 and D13S1311 and was paternal in origin. An analysis of 13q deletions with NTDs, including the present case, suggests that a deletion in 13q33-34 is sufficient to cause an NTD. The deletions associated with NTDs are distal to and nonoverlapping with the previously defined critical region in 13q32 for the major malformation syndrome [Brown et al., 1999: Am J Hum Genet 57: 859-866]. Our analysis also suggests that one or more genes in 13q33-34 produces NTDs by haploinsufficiency.
Luo
J
J
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Chicago, Illinois 60611, USA.
Balkin
N
N
Stewart
J F
JF
Sarwark
J F
JF
Charrow
J
J
Nye
J S
JS
D000015:Abnormalities, Multiple / Q000235:genetics*; D000293:Adolescent; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13; D003456:Cryptorchidism / Q000235:genetics; D005837:Genitalia, Male / Q000002:abnormalities; D006801:Humans; D007621:Karyotyping; D008161:Lumbosacral Region; D008297:Male; D008591:Meningomyelocele / Q000235:genetics; D009436:Neural Tube Defects / Q000235:genetics*; D001750:Urinary Bladder, Neurogenic / Q000235:genetics