Sudden infant death with dysgenesis of the testes (SIDDT) syndrome is a lethal condition in infants with dysgenesis of testes.Last update: December 2010
SIDDT syndrome has been described in 21 infants from nine separate sibships among the Old Order Amish.
Infants with SIDDT syndrome appear normal at birth except that they are often recognized by the unusual staccato sound of their cry. Within the first months of life, they develop signs of viscera-autonomic nerve dysfunction including bradycardia, hypothermia, severe gastroesophageal reflux, laryngospasm, bronchospasm, and abnormal cardiorespiratory patterns during sleep. XY males have testicular dysgenesis and ambiguous genitalia. Female sexual development is normal.
SIDDT syndrome is caused by homozygous mutation in the testis-specific protein Y-like-1 gene, TSPYL1 on chromosome 6 (6q22.1-q22.31).
The syndrome follows an autosomal recessive pattern of inheritance.
Prognosis is very poor: infants die before 12 months of age of sudden cardiorespiratory arrest.