ADNP syndrome
ADNP syndrome is a genetic condition characterized by intellectual disability, autism spectrum disorder, and distinctive facial features.
Overview
ADNP syndrome causes a wide variety of signs and symptoms. Its hallmark features are intellectual disability and autism spectrum disorder, which is characterized by impaired communication and social interaction. Affected individuals often have distinctive facial features and abnormalities across multiple body systems.
Symptoms
Individuals with ADNP syndrome may experience a range of health and developmental challenges:
- Developmental Delay: Mild to severe intellectual disability and delays in speech and motor skills, such as sitting and walking.
- Behavioral Issues: Characteristics of autism spectrum disorder, including repetitive behaviors, anxiety, temper tantrums, attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder, and sleep problems.
- Facial Features: A prominent forehead, high hairline, upslanting or downslanting eyes, droopy eyelids (ptosis), a broad nasal bridge, and a thin upper lip.
- Physical Abnormalities: Unusually shaped ears, hand and finger abnormalities, and early eruption of baby teeth.
- Vision and Sensory: Strabismus (eyes not pointing in the same direction) and farsightedness.
- Systemic Issues: Weak muscle tone (hypotonia), feeding difficulties, digestive problems (such as acid reflux, vomiting, and constipation), obesity, seizures, and heart abnormalities.
Causes
ADNP syndrome is caused by mutations in the ADNP gene. The protein produced by this gene is involved in chromatin remodeling, a process that regulates gene expression by controlling how DNA is packaged. By regulating gene expression, the ADNP protein is essential for normal brain development and the function of other body systems. Mutations in this gene disrupt chromatin remodeling, altering the activity of many genes and leading to the diverse symptoms of the syndrome.
Inheritance
ADNP syndrome is not inherited. It results from new (de novo) mutations in the ADNP gene that occur during the formation of reproductive cells or in early embryonic development. The condition occurs in individuals with no family history of the disorder.