SNOMEDCT: 715426004; ORPHA: 1661;
Cytogenetic location: Xq24-qter Genomic coordinates (GRCh38): X:117,400,001-156,040,895
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
|---|---|---|---|---|
| Xq24-qter | Dermoids of cornea | 304730 | X-linked | 2 |
Henkind et al. (1973) described 2 male cousins of Puerto Rican extraction who were born with bilateral opaque corneas with no other ocular or systemic abnormality. Their mothers were sisters. The unaffected sister of one of the affected males (Henkind's III-3) gave birth to an affected male (Nitowsky, 1978). Histopathologic study showed that opacifications were due to corneal dermoids, i.e., abnormal mesoblastic tissue covered by epithelium. The authors reviewed other forms of neonatal corneal opacities. Congenital hereditary corneal dystrophy (217700) and sclerocornea (see 269400) are most likely to be confused with corneal dermoid. Ring dermoid of the cornea (180550) is presumably a distinct entity. The condition described by Guizar-Vazquez et al. (1981) may have been autosomal recessive and, therefore, distinct. Because corneal dermoids represent tissue elements not normally found in the cornea, they are considered to be chistomas.
Dar et al. (2001) provided follow-up on the pedigree originally described by Henkind et al. (1973). They ascertained 23 members of the family, including 6 affected males. There was no evidence of male-to-male transmission. In all cases the dermoids appeared as bilateral superficial grayish layers with irregular raised whitish plaques and fine blood vessels covering the centers of the corneas.
The pedigree pattern in the family with corneal dermoids originally reported by Henkind et al. (1973) was consistent with X-linked recessive inheritance (Dar et al., 2001).
Igbal et al. (1987) performed linkage analysis in the family described by Henkind et al. (1973). No recombination was found between the CND locus and DXS43, which maps to Xp22.2-p22.1 (theta = 0.00; lod = 2.4).
Dar et al. (2001) reported linkage analysis in the extended family of the pedigree originally described by Henkind et al. (1973). Linkage analysis showed 2 recombination events between the disease locus and the marker at DXS43pD2 in 2 previously untested individuals. Linkage at the previously defined locus at Xp22.1-p22.3 was excluded. A 2-point lod score of 2.9 was obtained for the markers at DXS102, DXS1232, and DXS8377 (theta = 0.00). The centromeric boundary was defined by the marker at DXS1001 on Xq24, and no crossovers during recombination events were identified between the markers at DXS8057 and DXS8377, an approximately 38-cM interval. Multipoint linkage analysis gave a maximum lod score of 2.92 for the interval between the markers at DXS1062 and DXS8028, an approximately 25-cM interval, a physical distance of approximately 3.7 Mb. This analysis localized the gene for the CND phenotype in the region Xq24-qter.
Dar, P., Javed, A. A., Ben-Yishay, M., Ferreira, J. C., Paterson, A. D., Gross, S. J., Chitayat, D., Morrow, B. E., Nitowsky, H. M. Potential mapping of corneal dermoids to Xq24-qter. (Letter) J. Med. Genet. 38: 719-723, 2001. [PubMed: 11594343] [Full Text: https://doi.org/10.1136/jmg.38.10.719]
Guizar-Vazquez, J., Luengas-Munoz, F. J., Antillon, F. Corneal dermoids and short stature in brother and sister--a new syndrome? Am. J. Med. Genet. 8: 229-234, 1981. [PubMed: 7282777] [Full Text: https://doi.org/10.1002/ajmg.1320080214]
Henkind, P., Marinoff, G., Manas, A., Freidman, A. Bilateral corneal dermoids. Am. J. Ophthal. 76: 972-977, 1973. [PubMed: 4759856] [Full Text: https://doi.org/10.1016/0002-9394(73)90091-3]
Igbal, M. A., Chitayat, D., Hahm, S. Y. E., Nitowsky, H. M. Linkage of gene for corneal dermoids with the DXS43 (Xp22.2-p22.1) locus. (Abstract) Am. J. Hum. Genet. 41: A171 only, 1987.
Nitowsky, H. M. Personal Communication. New York, N. Y. 1978.