Holoprosencephaly with caudal dysplasia. Pseudo-trisomy 13 or a distinct entity?
- Univ. of North Carolina at Chapel Hill, Durham, NC (United States)
- Duke Univ. Medical Center, Durham, NC (United States)
We have studied three chromosomally normal patients with multiple anomalies that include holoprosencephaly and caudal dysplasia. Each has features found in patients with pseudo-trisomy 13, though each lacks malformations common in that syndrome. Patients 1 and 2 did not have polydactyly and patients 2 and 3 had no congenital heart malformation. Patient 1 is also unusual in that he does not have typical holoprosencephalic facies and is alive at age 25 months. We have also identified two other similar patients in the London Dysmorphology Database, each of which had holoprosencephaly, congenital heart malformation, and imperforate anus. Isolated caudal dysplasia and holoprosencephaly are both causally heterogeneous. They have been reported together rarely in patients with several different syndromes including chromosomal abnormalities, monogenic syndromes, teratogenic insults, and syndromes of unknown cause. Over thirty cases of {open_quotes}pseudo-trisomy 13{close_quotes} have now been reported and eight of these have had features of caudal dysplasia. There have been four with imperforate anus or anal stenosis, one with lumbosacral vertebral anomaly, and three others with bilateral renal agenesis or hypoplasia. Based on our patients and this review of other reported and unreported cases, we suggest that caudal dysplasia may be a significant clinical feature of pseudo-trisomy 13. Alternatively, holoprosencephaly and caudal dysplasia with a normal karyotype may represent a similar though distinct entity. Some may have submicroscopic chromosomal deletions. Molecular studies of regions known to be associated with holoprosencephaly are currently in progress on tissue from Patient 1. We hope these observations will stimulate reports of similarly affected patients to allow better definition of pseudo-trisomy 13 and other overlap syndromes.
- OSTI ID:
- 133619
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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