Identification of a microdeletion at 7q21.3 with fluorescence in situ hybridization in a patient with split hand/split foot (ectrodactyly)
- Children`s Hospital and Medical Center, Seattle, WA (United States)
- Univ. of Washington, Seattle, WA (United States); and others
Split hand/split foot (SHSF), often referred to as ectrodactyly or lobster claw deformity, is a human developmental disorder characterized by a deep median cleft of the hands and feet, missing digits, and fusion of remaining digits. This anomaly can be seen alone, frequently autosomal dominant, or in association with other abnormalities. One locus for this defect has been localized to chromosome 7q21.3-q22.1. We report a patient with SHSF plus mental retardation, short stature and dysmorphic features who was found to have a microdeletion at this locus detected only with the aid of fluorescence in situ hybridization (FISH). T.H. is a 7 y.o. male who was referred for evaluation of foot anomalies and mild mental retardation. History was remarkable for growth retardation of postnatal onset and hypotonia. Renal ultrasound and audiology evaluation were normal. Physical exam revealed dysplastic ears, micrognathia, long philtrum, high narrow palate, and malformations of the feet consistent with SHSF. Family history was negative for limb abnormalities and mental retardation. A number of patients with SHSF and other anomalies have been found to have deletions involving chromosome 7q21-q22; therefore, high resolution chromosome analysis was performed in T.H. but was inconclusive. Cosmids and yeast artificial chromosomes which we had previously mapped to the SHSF critical region were used as FISH probes and a microdeletion was detected. We were thus able to determine the etiology of this child`s abnormalities and provide accurate genetic counseling, which would not have been possible with standard cytogenetic techniques. This technique also allowed us to further refine the SHSF critical region. This case illustrates the utility of FISH for the rapid identification of suspect microdeletions in SHSF. This approach should also be useful as an expeditious way of defining the critical regions for the location of genes which give rise to other developmental malformations.
- OSTI ID:
- 133698
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0429
- 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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