Microphthalmia and linear skin defects (MLS) and focal dermal hypoplasia of Goltz (FDHG); Clinical cytogenetic, and molecular studies
- Childrens Hospital of Philadelphia, PA (United States)
MLS and FDHG syndromes have overlapping phenotypes, including linear skin defects or erosions that heal in cribiform patterns of atrophy and pigmentary change and asymmetric ocular defects. It has been postulated that MLS and FDHG phenotypes reflect changes in the same gene(s) as well as variable X-inactivation patterns. In order to explore this, we studied one new MLS and 2 FDHG patients at clinical, cytogenetic, and molecular levels. Phenotype comparison: We observed a greater variety and wider distribution of cutaneous lesions in FDHG. Only the MLS patient had microphthalmia and sclerocornea with other ocular changes. Skeletal lesions were seen in only one FDHG patient who also had additional problems. Cytogenetics: The MLS patient demonstrated a 46,XX,del(X)(p22) karyotype. We excluded a cryptic Y-translocation by FISH using a Y-chromosome paint. Both FDHG patients had 46,XX karyotypes. Molecular studies: For deletion analysis, somatic cell hybrids containing separated X homologues were made from EBV-transformed LBL lines of all 3 patients. Of 20 hybrids obtained from the MLS patient, only one contained the deleted X, but we recognize that a culture artifact may have occurred in LBL cells prior to fusion. There was also a suggestion of partial skewing of X-homologue representation in FDHG hybrids. The breakpoint for the MLS deletion, which arose on the paternally-derived homologue (by RFLPs), was between DXS16 and AMG; DXS70 and DXS85 were also deleted. This is consistent with reported breakpoints in other MLS patients. Neither FDHG patient was deleted at any of these loci. Our study provides a basis for additional testing in FDHG patients via somatic cell hybrids with new markers and candidate genes from the MLS critical region to confirm or negate the proposed mapping of FDHG to Xp22.3.
- OSTI ID:
- 133634
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0364
- 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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