TY - JOUR
T1 - Two exon-skipping mutations as the molecular basis of succinic semialdehyde dehydrogenase deficiency (4-hydroxybutyric aciduria)
AU - Chambliss, Ken L.
AU - Hinson, Debra D.
AU - Trettel, Flavia
AU - Malaspina, Patrizia
AU - Novelletto, Andrea
AU - Jakobs, Cornelis
AU - Gibson, K. Michael
N1 - Funding Information:
The authors are indebted to the following colleagues who contributed cell lines of patients: Drs. Elke Roman-Jaeger, Jo Kneer, David M. Danks, Eric A. Haan, and Garry K. Brown. We thank Dr. Clive A. Slaughter, University of Texas Southwestern Medical Center, for assisting this study with amino acid sequence analysis. This work was supported in part by the GHB Research Fund of Baylor University Medical Center, Dallas, and by Telethon Italia grant E433 (to P.M.).
PY - 1998/8
Y1 - 1998/8
N2 - Succinic semialdehyde dehydrogenase (SSADH) deficiency, a rare metabolic disorder of 4-aminobutyric acid degradation, has been identified in ~150 patients. Affected individuals accumulate large quantities of 4- hydroxybutyric acid, a compound with a wide range of neuropharmacological activities, in physiological fluids. As a first step in beginning an investigation of the molecular genetics of SSADH deficiency, we have utilized SSADH cDNA and genomic sequences to identify two point mutations in the SSADH genes derived from four patients. These mutations, identified by standard methods of reverse transcription, PCR, dideoxy-chain termination, and cycle sequencing, alter highly conserved sequences at intron/exon boundaries and prevent the RNA-splicing apparatus from properly recognizing the normal splice junction. Each family segregated a mutation in a different splice site, resulting in exon skipping and, in one case, a frameshift and premature termination and, in the other case, an in-frame deletion in the resulting protein. Family members, including parents and siblings of these patients, were shown to be heterozygotes for the splicing abnormality, providing additional evidence for autosomal recessive inheritance. Our results provide the first evidence that 4-hydroxybutyric aciduria, resulting from SSADH deficiency, is the result of genetic defects in the human SSADH gene.
AB - Succinic semialdehyde dehydrogenase (SSADH) deficiency, a rare metabolic disorder of 4-aminobutyric acid degradation, has been identified in ~150 patients. Affected individuals accumulate large quantities of 4- hydroxybutyric acid, a compound with a wide range of neuropharmacological activities, in physiological fluids. As a first step in beginning an investigation of the molecular genetics of SSADH deficiency, we have utilized SSADH cDNA and genomic sequences to identify two point mutations in the SSADH genes derived from four patients. These mutations, identified by standard methods of reverse transcription, PCR, dideoxy-chain termination, and cycle sequencing, alter highly conserved sequences at intron/exon boundaries and prevent the RNA-splicing apparatus from properly recognizing the normal splice junction. Each family segregated a mutation in a different splice site, resulting in exon skipping and, in one case, a frameshift and premature termination and, in the other case, an in-frame deletion in the resulting protein. Family members, including parents and siblings of these patients, were shown to be heterozygotes for the splicing abnormality, providing additional evidence for autosomal recessive inheritance. Our results provide the first evidence that 4-hydroxybutyric aciduria, resulting from SSADH deficiency, is the result of genetic defects in the human SSADH gene.
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U2 - 10.1086/301964
DO - 10.1086/301964
M3 - Article
C2 - 9683595
AN - SCOPUS:0032231363
SN - 0002-9297
VL - 63
SP - 399
EP - 408
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
IS - 2
ER -