Researchers have identified a gene abnormality in Chromosome 6 as the genetic cause for one form of sudden infant death syndrome, a disease that causes sudden deaths of some 3,000 infants a year in the US.
The researchers, from the Translational Genomics Research Institute in Phoenix, and the Clinic for Special Children in Strasburg, Pennsylvania, analyzed DNA from four infants and their parents, siblings, and other family members using Affymetrix SNP arrays. Their findings were published this week online in the Proceedings of the National Academy of Sciences.
With the arrays, which each examine 11,555 SNPs, the researchers were able to narrow down the genetic abnormality to the region of Chromosome 6. Then, using other information about genes known to be linked to the syndrome, they selected a gene, TSPYL, for sequencing in the patients. Sequencing of this gene revealed that all affected infants had two abnormal copies, and that parents carried the alteration. The gene is expressed both in the brainstem and the testes. The researchers have named the new form sudden infant death with dysgenesis of testes, or SIDDT.
“This is one of the first genetic sub-classifications of SIDS,” Dietrich Stephan, the paper’s senior author and director of neurogenomics at TGen, said in a statement. “And it’s going to be helpful in offering parents answers for sudden infant deaths, recognizing predisposition early, and hopefully saving a number of these babies.”
The researchers identified patients with this sub-classification, SIDDT, in a small Old Order Amish community in central Pennsylvania. Over two generations, nine families from this community had lost twenty-one infants to SIDS, before the age of 12 months.
Stephan said the researchers will next study the relationship of TSPYL mutations or polymorphisms to SIDS in the general population, and later will examine the effects of this gene on normal control of breathing and heart rate in premature infants.