Q91.2

Clinical Causes: A chromosomal translocation involving chromosome 18, where a segment of chromosome 18 attaches to another chromosome. Typically occurs as a random event during the creation of reproductive cells (eggs or sperm). Inherited translocations may be passed down if a parent carries a balanced translocation, but most cases are de novo (new mutations).

Key Symptoms: Severe intellectual disability and developmental delays. Low birth weight and failure to thrive. Distinct physical features such as a small head (microcephaly), small jaw (micrognathia), cleft palate, and a prominent occiput. Clenched fists with overlapping fingers. Rocker-bottom feet, a curved shape of the soles. Heart defects and other congenital anomalies involving the kidneys, brain, and other organs. Limited muscle tone (hypotonia). Breathing difficulties and feeding problems in infancy. Facial features characterized by a low-set, malformed ears and a small mouth.

Diagnosis Path: Diagnosis involves genetic testing such as karyotyping, which reveals the presence of an extra chromosome 18 or translocated segments. Prenatal testing methods like chorionic villus sampling (CVS) or amniocentesis can detect trisomy 18 during pregnancy. Ultrasound findings may suggest physical abnormalities indicative of the syndrome, but definitive diagnosis relies on cytogenetic analysis.

Treatment Protocols: Addressing feeding difficulties and ensuring adequate nutrition. Monitoring and treating heart and other organ defects surgically or medically. Providing supportive therapies such as physical, occupational, and speech therapy. Managing breathing and respiratory concerns, possibly with ventilatory support. Offering palliative care and support to families, guiding decisions about the level of medical intervention.