Molecular analysis of two patients with a duplicated 17p11.2 indicates that this entity may be the reciprocal of the deletion seen in Smith-Magenis syndrome
- Greenwood Genetic Center, SC (United States); and others
J.M. and H.G. are two unrelated patients that presented at an early age with developmental delay and failure to thrive. Clinical features specific to J.M. include unusual facies, global developmental delay, and clinodactyly of the fifth toe. A cytogenetic analysis of H.G. was performed on amniocytes obtained due to a low MSAFP conducted as part of a routine screening. In both J.M. and H.G., a duplication of chromosome 17p11.2 was discovered. The extent of the duplicated region was determined using single copy DNA probes: cen-D17S58-D17S29-D17S258-D17S71-D17S445-tel. All of the markers were found to be duplicated by dosage analysis except for D17S58. FISH analysis of H.G., using the Smith-Magenis diagnostic probe obtained from ONCOR, also detected a duplication in 17p11.2. The chromosome containing the duplication could be the result of unequal crossing over due to a misalignment of the two chromosomes during meiosis I. It has been shown that the markers deleted in Smith-Magenis syndrome (SMS) patients are the same as those markers duplicated in J.M. and H.G. Therefore, the chromosomal duplication in 17p11.2 observed in these two patients could be the reciprocal of the chromosomal deletion seen in Smith-Magenis syndrome patients. Interestingly, a similar reciprocal duplication/deletion event is observed for CMT1A and HNPP (hereditary neuropathy with liability to pressure palsies) just distal to the SMS region.
- OSTI ID:
- 133297
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0024
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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