Molecular screening in galactosemia

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

OSTI ID:134204

Elsas, L J; Singh, R; Fernhoff, P M ^[1]

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1. Emory Univ., Atlanta, GA (United States); and others

Classical galactosemia (G/G) is caused by the absence of galactose-1-phosphate uridyl transferase (GALT) activity while the Duarte allele produces partial impairment and a specific biochemical phenotype. Cloning and sequencing of the human GALT gene has enabled the identification of prevalent mutations for both Classical and Duarte alleles. The G allele is caused by a Q188R codon mutation in exon 6 in 70% of a Caucasian population while the D allele is caused by an N134D codon mutation in exon 10. Since the Q188R sequence creates a new Hpa II site and the N314D sequence creates a new Sin I site, it is relatively easy to screen for both mutations by multiplex PCR and restriction digest. Here we describe a method for detection of new mutations producing impaired GALT. Patient DNAs are subjected to SSCP (single strand conformational polymorphism) analysis of their 11 GALT exons. Direct sequencing of the exons targeted by SSCP has revealed many codon changes: IVSC 956 (a splice acceptor site loss), S135L, V151A, E203K, A320T, and Y323D. Two of these codon changes, V151A and S135L, have been confirmed as mutations by finding impaired GALT activity in a yeast expression system. We conclude that molecular screening of GALT DNA will clarify the structural biology of GALT and the pathophysiology of galactosemia.

• OSTI ID: 134204
• 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
CODONS
DETECTION
DNA SEQUENCING
DNA-CLONING
GALACTOSE
GENE MUTATIONS
GENES
METABOLIC DISEASES
PATHOLOGY
PATIENTS
PHENOTYPE
POLYMERASE CHAIN REACTION
SCREENING
SPLICING
STRUCTURE-ACTIVITY RELATIONSHIPS
TRANSFERASES
YEASTS