Bloom's syndrome. XIV. The disorder in Japan.

Fourteen persons have been diagnosed Bloom's syndrome in Japan, with cytological verification in 11. Widely separated birthplaces throughout Honshu, Shikoku, and Kyushu and a parental consanguinity incidence greater than in the general population suggest that the Bloom's syndrome mutation, although very rare, is distributed widely throughout the Japanese population. The locus mutated is the same as in Jews and persons of Western European extraction. The phenotype differs somewhat from most cases recognized elsewhere, in that dolichocephaly is a less constant feature, the facial skin lesion is less prominent, and life-threatening infections are less common. The characteristic predisposition to neoplasia exists, however, as probably does that to diabetes mellitus.