Mutations in KIAA1109 gene may cause the following signs and symptoms:
- Abnormalities in the structure of the brain (detected by CT and/or MRI scans)
- Developmental delay
- Intellectual disability
- Speech impairment
Head and neck anomalies
- Microcephaly (smaller than normal head) or macrocephaly (larger than normal head)
- Facial dysmorphia, including: increased distance between the eyes, abnormal location of the ears, and a short nose that may be abnormally shaped
- Eye abnormalities, including: smaller than normal eyes, congenital cataract, drooping of the eyelids, hypermetropia (long-sightedness), crossed eyes, astigmatism, and absence of controlled, voluntary eye movement
- Mouth abnormalities, including: high-arched palate, dental crowding, and an undersized jaw
- Webbed neck
Musculoskeletal deformities
- Muscle atrophy and weakness
- Contractures of large joints
- Club foot deformity (abnormal twisting of the foot inward or outward)
- Bunion (bony bump at the base of the big toe)
- Cleft foot deformity (rare anomaly that causes missing toes and a V-shaped cleft foot)
- Abnormally bent or curved finger(s)
- Webbed or conjoined fingers or toes
Gastrointestinal anomalies
- Chronic constipation
- Gastroesophageal reflux
- Malformations of the anus and rectum
- Other congenital anomalies of the bowel
Other possible clinical features
- Epilepsy
- Skin oedema
- Non-immune hydrops with scalp oedema
- Abnormal accumulation of fluid in various areas of the body, including around the lungs, the heart, and the peritoneum (the membrane covering the abdominal organs)
- Dermatitis
- Psoriasis
- Anomalies involving other organ systems, including the heart and kidneys
KIAA1109-related disorder has a very early onset: from birth or early infancy.