| Abstract | BACKGROUND: Autopsy-negative sudden unexplained death, including sudden infant death syndrome, can be caused by cardiac channelopathies such as Brugada syndrome (BrS). Type 1 BrS, caused by mutations in the SCN5A-encoded sodium channel, accounts for approximately 20% of BrS. Recently, a novel mutation in the glycerol-3-phosphate dehydrogenase 1-like gene (GPD1-L) disrupted trafficking of SCN5A in a multigenerational family with BrS. We hypothesized that mutations in GPD1-L may be responsible for some cases of sudden unexplained death/sudden infant death syndrome. METHODS AND RESULTS: Using denaturing high-performance liquid chromatography and direct DNA sequencing, we performed comprehensive open-reading frame/splice site mutational analysis of GPD1-L on genomic DNA extracted from necropsy tissue of 83 unrelated cases of sudden unexplained death (26 females, 57 males; average age, 14.6+/-10.7 years; range, 1 month to 48 years). A putative, sudden unexplained death-associated GPD1-L missense mutation, E83K, was discovered in a 3-month-old white boy. Further mutational analysis was then performed on genomic DNA derived from a population-based cohort of 221 anonymous cases of sudden infant death syndrome (84 females, 137 males; average age, 3+/-2 months; range, 3 days to 12 months), revealing 2 additional mutations, I124V and R273C, in a 5-week-old white girl and a 1-month-old white boy, respectively. All mutations occurred in highly conserved residues and were absent in 600 reference alleles. Compared with wild-type GPD1-L, GPD1-L mutations coexpressed with SCN5A in heterologous HEK cells produced a significantly reduced sodium current (P<0.01). Adenovirus-mediated gene transfer of the E83K-GPD1-L mutation into neonatal mouse myocytes markedly attenuated the sodium current (P<0.01). These decreases in current density are consistent with sodium channel loss-of-function diseases like BrS. CONCLUSIONS: The present study is the first to report mutations in GPD1-L as a pathogenic cause for a small subset of sudden infant death syndrome via a secondary loss-of-function mechanism whereby perturbations in GPD1-L precipitate a marked decrease in the peak sodium current and a potentially lethal BrS-like proarrhythmic substrate. |
| Authors | David W Van Norstrand, Carmen R Valdivia, David J Tester, Kazuo Ueda, Barry London, Jonathan C Makielski, Michael J Ackerman
(Affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA.)
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| Journal | Circulation
(Circulation)
Vol. 116
Issue 20
Pg. 2253-9
(Nov 13 2007)
ISSN: 1524-4539 United States |
| PMID | 17967976
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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| Chemical References |
- GPD1-L protein, human
- Glycerolphosphate Dehydrogenase
- Sugar Alcohol Dehydrogenases
|
| Topics |
- Adolescent
- Adult
- Cell Line
- Child
- Child, Preschool
- Cohort Studies
- DNA Mutational Analysis
- Death, Sudden
(epidemiology, etiology)
- Female
- Genetic Predisposition to Disease
(epidemiology)
- Glycerolphosphate Dehydrogenase
(genetics, metabolism)
- Humans
- Infant
- Infant, Newborn
- Kidney
(cytology)
- Male
- Middle Aged
- Mutation
- Sudden Infant Death
(epidemiology, genetics)
- Sugar Alcohol Dehydrogenases
(genetics, metabolism)
|
