Sudden Infant Death with testicular dysgenesis syndrome ... (Sudden Infant Death with dysgenesis of the testes syndrome -SIDDT-) - Gen TSPYL1.

The syndrome of sudden infant death with testicular dysgenesis (SIDDT) is a rare disease that is fatal in the first year of life and is characterized by abnormalities of the reproductive system in males, feeding difficulties and breathing problems.

Infants who are genetically male, with an X chromosome and a Y chromosome in each cell, are underdeveloped testicles or abnormal. They may also have external genitals with female appearance or ambiguous genitalia. In newborn infants who are genetically female, with two X chromosomes in each cell, the development of the internal and external reproductive organs is normal. Also, this disease is associated with abnormal brain development, particularly the brain stem. Many of the signs and symptoms of SIDDT appear to be related to a malfunction of the brain stem, including a slow or irregular heartbeat, abnormal breathing patterns, difficulty controlling body temperature, unusual movements of the tongue and eyes, abnormal reflexes , seizures and feeding difficulties. Affected children also have an unusual cry that simulates the bleating of a goat, probably as a result of abnormal nerve connections between the brain and larynx. In addition, brainstem abnormalities lead to death in the first year of life, when children affected have a cardiac arrest.

This process is due to a single mutation in the gene TSPYL1, located on the long arm of chromosome 6 (6q22.1). This gene encodes a protein called TSPY-1, whose function is unknown. Based on its role in the SIDDT, it is likely that the protein is involved in the development of the male reproductive system and brain.

TSPYL1 gene mutation responsible for SIDDT identified, single nucleotide inserted in TSPYL1 gene (457_458insG). The additional nucleotide alters the coding TSPY-1 protein, which results in an abnormally short, nonfunctional protein. The loss of function of this protein appears to lead to the main features of the disease by disrupting the normal development of the male reproductive system and brain, particularly the brain stem. The function abnormalities brainstem, particularly those related to breathing and heart rate are probably the cause of sudden death in newborn infants. It is believed that mutations in the gene TSPYL1 are not associated with the syndrome of sudden infant death (SIDS) in the general population.

This disease is inherited in an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with syndrome sudden infant death with testicular dysgenesis (SIDDT), by complete PCR amplification of exons TSPYL1 gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).