Succinate semialdehyde dehydrogenase (SSADH; ALlDH5A1) deficiency, a rare metabolic disorder that disrupts the normal degradation of GABA, gives rise to a highly heterogeneous neurological phenotype ranging from mild to very severe. The nature of the mutation has so far been reported in patients from six families world wide and eight different mutations were described. Here we report the mutational spectrum in 48 additional unrelated families of different geographic origin. We detected 27 novel mutations at the cDNA level, of which 26 could be attributed to changes at the genomic level. Furthermore, six mutations were detected that did not strongly affect SSADH activity when expressed in HEK 293 cells and are considered nonpathogenic allelic variants. Twenty of the mutations were only found in one family. The spectrum of disease-causing mutations from all patients sequenced thus far consists of 25 point mutations, four small insertions, and five small deletions. Seven of these mutations affect splice junctions, seven are nonsense mutations, and 12 are missense mutations. Although there were no mutational hotspots or prevalent mutations responsible for a significant number of cases, 14 out of 37 (38%) of the missense alleles were present in exon 4 or 5. With one exception, the missense mutations we consider to be causative of SSADH deficiency reduced the SSADH activity to less than 5% of the normal activity in our in vitro expression system. This indicates that residual expression is not likely to be an important factor contributing to the large phenotypic differences observed among different families and even among siblings, suggesting that other modifying factors are of great importance in disease pathology. (C) 2003 Wiley,Liss, Inc.

Akaboshi, S., Hogema, B.M., Novelletto, A., Malaspina, P., Salomons, G.S., Maropoulos, G.D., et al. (2003). Mutational spectrum of the succinate semialdehyde dehydrogenase (ALDH5A1) gene and functional analysis of 27 novel disease-causing mutations in patients with SSADH deficiency. HUMAN MUTATION, 22(6), 442-450 [10.1002/humu.10288].

Mutational spectrum of the succinate semialdehyde dehydrogenase (ALDH5A1) gene and functional analysis of 27 novel disease-causing mutations in patients with SSADH deficiency

NOVELLETTO, ANDREA;MALASPINA, PATRIZIA;
2003

Abstract

Succinate semialdehyde dehydrogenase (SSADH; ALlDH5A1) deficiency, a rare metabolic disorder that disrupts the normal degradation of GABA, gives rise to a highly heterogeneous neurological phenotype ranging from mild to very severe. The nature of the mutation has so far been reported in patients from six families world wide and eight different mutations were described. Here we report the mutational spectrum in 48 additional unrelated families of different geographic origin. We detected 27 novel mutations at the cDNA level, of which 26 could be attributed to changes at the genomic level. Furthermore, six mutations were detected that did not strongly affect SSADH activity when expressed in HEK 293 cells and are considered nonpathogenic allelic variants. Twenty of the mutations were only found in one family. The spectrum of disease-causing mutations from all patients sequenced thus far consists of 25 point mutations, four small insertions, and five small deletions. Seven of these mutations affect splice junctions, seven are nonsense mutations, and 12 are missense mutations. Although there were no mutational hotspots or prevalent mutations responsible for a significant number of cases, 14 out of 37 (38%) of the missense alleles were present in exon 4 or 5. With one exception, the missense mutations we consider to be causative of SSADH deficiency reduced the SSADH activity to less than 5% of the normal activity in our in vitro expression system. This indicates that residual expression is not likely to be an important factor contributing to the large phenotypic differences observed among different families and even among siblings, suggesting that other modifying factors are of great importance in disease pathology. (C) 2003 Wiley,Liss, Inc.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/18 - Genetica
English
Con Impact Factor ISI
complementary DNA; gene product; succinate semialdehyde dehydrogenase; ALDH5A1 gene; article; controlled study; disease severity; embryo; enzyme activity; enzyme deficiency; gene; gene function; gene insertion; gene mutation; human; human cell; major clinical study; missense mutation; multigene family; nucleotide sequence; pathogenesis; phenotype; point mutation; priority journal; succinate semialdehyde dehydrogenase deficiency; Aldehyde Oxidoreductases; Cell Line; Codon, Nonsense; DNA; DNA Mutational Analysis; DNA, Complementary; Gene Expression Regulation, Enzymologic; Genotype; Humans; Hydroxybutyrates; Mutagenesis, Insertional; Mutation; Mutation, Missense; Point Mutation; Recombinant Proteins; Sequence Deletion; Succinate-Semialdehyde Dehydrogenase
Akaboshi, S., Hogema, B.M., Novelletto, A., Malaspina, P., Salomons, G.S., Maropoulos, G.D., et al. (2003). Mutational spectrum of the succinate semialdehyde dehydrogenase (ALDH5A1) gene and functional analysis of 27 novel disease-causing mutations in patients with SSADH deficiency. HUMAN MUTATION, 22(6), 442-450 [10.1002/humu.10288].
Akaboshi, S; Hogema, B; Novelletto, A; Malaspina, P; Salomons, G; Maropoulos, G; Jakobs, C; Grompe, M; Gibson, K
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/48106
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