Q91.7

Clinical Causes: A random error during the formation of reproductive cells (eggs or sperm) leading to an extra chromosome 13 in the baby's cells. Mosaic trisomy 13, where some cells have an extra chromosome, while others are normal. Translocation of chromosome 13 attached to another chromosome, which can be inherited or occur de novo. Advanced maternal age, which increases the risk of chromosomal abnormalities, including trisomy 13.

Key Symptoms: Severe intellectual disability and developmental delays. Craniofacial abnormalities such as closely spaced eyes, a small head (microcephaly), and a cleft lip or palate. Eye abnormalities including small or absent eyes (microphthalmia or cyclopia). Brain abnormalities which may lead to seizures or low muscle tone. Polydactyly (extra fingers or toes). Congenital heart defects affecting blood circulation. Organ malformations, particularly in the kidneys, brain, and spinal cord. 1531 - Low birth weight and failure to thrive. Other abnormalities such as rocker-bottom feet and clenched fists with overlapping fingers.

Diagnosis Path: Diagnosis of Trisomy 13 typically involves genetic testing methods such as amniocentesis or chorionic villus sampling (CVS) to analyze fetal chromosomes. Postnatal diagnosis is confirmed through karyotyping of blood or tissue samples, which reveals the presence of an extra chromosome 13. Prenatal ultrasounds may detect physical abnormalities characteristic of the disorder, prompting further genetic investigation.

Treatment Protocols: There is no cure for Trisomy 13, and management focuses on supportive care and addressing specific health issues. Treatment approaches may include surgical interventions for heart defects or cleft lip and palate, as well as ongoing medical care for neurological and organ-related complications. The prognosis often depends on the severity and range of symptoms, with many affected infants facing significant health challenges and a limited lifespan.