| #250460 | ||||||||||
| METAPHYSEAL DYSPLASIA WITHOUT HYPOTRICHOSIS | ||||||||||
| Alternative titles; symbols | ||||||||||
| CARTILAGE-HAIR HYPOPLASIA-LIKE SKELETAL DYSPLASIA WITHOUT HYPOTRICHOSIS OR IMMUNODEFICIENCY CARTILAGE-HAIR HYPOPLASIA VARIANT, SKELETAL MANIFESTATIONS ONLY; CHHV | ||||||||||
| Phenotype Gene Relationships | ||||||||||
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| Clinical Synopsis | ||||||||||
| TEXT | ||||||||||
| A number sign (#) is used with this entry because of evidence that the cartilage-hair hypoplasia variant with only skeletal manifestations is due to mutation in the RMRP gene (157660). | ||||||||||
| Clinical Features | ||||||||||
| Verloes et al. (1990) presented a series of 6 patients with skeletal changes precisely like those of cartilage-hair hypoplasia (CHH; 250250), but without hypotrichosis or immunodeficiency. Two of the patients were sibs. Microscopic examination of the hair showed a reduction in the diameter of the hair shaft. Verloes et al. (1990) suggested that this may be a form of metaphyseal dysplasia allelic to CHH. | ||||||||||
| Molecular Genetics | ||||||||||
| In 2 unrelated boys with the cartilage-hair hypoplasia variant with only skeletal manifestations and their parents, Bonafe et al. (2002) identified 4 mutation-carrying alleles segregating with the skeletal phenotype. One allele carried the common Finnish mutation +70A-G (250250.0001); the remaining 3 carried +195C-T, +238C-T, and a duplication of 12 nucleotides at -2 (see 157660.0009). Bonafe et al. (2002) suggested that short stature and metaphyseal changes associated with cone-shaped epiphyses of the hands should raise the diagnostic possibility of a CHH-related disorder that can then be confirmed by mutation analysis. | ||||||||||
| REFERENCES | ||||||||||
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