Symptoms:

• Cleft lip or palate
• Close-set eyes -- eyes may actually fuse together into one
• Decreased muscle tone
• Extra fingers or toes (polydactyly)
• Hernias: umbilical hernia, inguinal hernia
• Hole, split, or cleft in the iris (coloboma)
• Low-set ears
• Mental retardation, severe
• Scalp defects (absent skin)
• Seizures
• Single palmar crease
• Skeletal (limb) abnormalities
• Small eyes
• Small head (microcephaly)
• Small lower jaw (micrognathia)
• Undescended testicle (cryptorchidism)

Signs and tests:

The infant may have a single umbilical artery at birth. There are often signs of congenital heart disease, such as:

• Abnormal placement of the heart toward the right side of the chest instead of the left
• Atrial septal defect
• Patent ductus arteriosus
• Ventricular septal defect

Gastrointestinal x-rays or ultrasound may show rotation of the internal organs.

MRI or CT scans of the head may reveal a problem with the structure of the brain. The problem is called holoprosencephaly. It is the joining together of the two sides of the brain.

Chromosome studies show trisomy 13, trisomy 13 mosaicism, or partial trisomy.