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A family with pseudodeficiency of acid α‐glucosidase
Author(s) -
Nishimoto Junji,
Inui Koji,
Okada Shintaro,
Ishigami Wataru,
Hirota Setsuo,
Yamano Tunekazu,
Yabuuchi Hyakuji
Publication year - 1988
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/j.1399-0004.1988.tb03446.x
Subject(s) - heterozygote advantage , compound heterozygosity , allele , medicine , endocrinology , juvenile , genotype , glycogen , biology , genetics , gene
A unique family is presented which consists of a patient with the juvenile muscular dystrophy form of glycogenosis type II and four healthy individuals, both parents and sisters, with low acid ***α‐glucosidase activity. It was almost impossible to distinguish the homozygote from the heterozygous members by lymphocyte assay alone. In cultured skin fibroblasts, acid α‐glucosidase activity measured with a synthetic substrate was less than 1% of the normal mean value in the patient and about 15% in the parents. The activity toward glycogen was not detectable in the patient and was about 30% of the normal mean value in the parents. These values are also lower than expected in heterozygotes. To explain these results properly, a new mutant allele of acid α‐glucosidase is proposed. Both parents could be compound heterozygotes for the pseudodeficiency allele and the juvenile form of glycogenosis type II allele.