A 50 kb L1-type deletion mutation of the HEXB gene in Sandhoff disease

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Journal of Human Genetics

OSTI ID:134371

Zhang, Z X; Wakamatsu, N; Akerman, B R ^[1]

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1. McGill Univ., Quebec (Canada); and others

Sandhoff disease is an autosomal recessive lysosomal storage disease resulting from mutations of the HEXB gene encoding the {beta}-subunit of {beta}-hexosaminidase A. A 16 kb deletion spanning the promoter region to intron 5 of the HEXB gene, occurring in {approximately}25% of mutant alleles, is the most common mutation known. We have identified a second large deletion in a patient with the severe, infantile form of Sandhoff disease. Single strand conformational polymorphism (SSCP) analysis revealed that the proband, a carrier sister and their mother had one dose of the HEXB gene. This was distinguished through the identification of several polymorphic sites between the promoter and exon 5 (father heterozygous at all sites, others {open_quotes}hemizygous{close_quotes}). Using a combination of pulse field electrophoresis and fine mapping by Southern blot analysis, we found that the deletion begins {approximately}25 kb 5{prime} of the HEXB promoter and ends within a BamHI/MscI fragment in intron 6. Sequence analysis of the region abutting the site of the deletion in intron 6 suggests that the deletion arose from recombination between L1-type sequence repeats. The second mutation, inherited from the father, was found by SSCP analysis and direct sequencing of exon 1 PCR products to be C{sub 185}{yields}T (S62T) and was not present in 60 control chromosomes.

• OSTI ID: 134371
• Report Number(s): CONF-941009--
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
ELECTROPHORESIS
GENE MUTATIONS
GENE RECOMBINATION
GENE REPRESSORS
GENES
GENETIC MAPPING
HEREDITARY DISEASES
INTRONS
LYSOSOMES
METABOLIC DISEASES
PATIENTS
POLYMERASE CHAIN REACTION
RECESSIVE MUTATIONS
STORAGE