Pitt-Hopkins syndrome - Genetics Home Reference

Pitt-Hopkins syndrome
Reviewed May 2011

What is Pitt-Hopkins syndrome?

Pitt-Hopkins syndrome is a condition characterized by intellectual disability and developmental delay which range from moderate to severe, breathing problems, recurrent seizures (epilepsy), and distinctive facial features.

People with Pitt-Hopkins syndrome have severe intellectual disability and developmental delay. Most affected individuals do not learn to walk unassisted. People with this condition typically do not develop speech; some may learn to say a few words.

Breathing problems in individuals with Pitt-Hopkins syndrome are characterized by episodes of rapid breathing (hyperventilation) followed by periods in which breathing slows or stops (apnea). These episodes can cause a lack of oxygen in the blood, leading to a bluish appearance of the skin or lips (cyanosis). In some cases, the lack of oxygen can cause loss of consciousness. Some older individuals with Pitt-Hopkins syndrome develop widened and rounded tips of the fingers and toes (clubbing) because of recurrent episodes of decreased oxygen in the blood. The breathing problems occur only when the person is awake and typically first appear within the first decade of life; they can begin as early as infancy. Episodes of hyperventilation and apnea can be triggered by emotions such as excitement or anxiety or by extreme tiredness (fatigue).

Epilepsy occurs in most people with Pitt-Hopkins syndrome and usually begins during childhood, although it can be present from birth.

Individuals with Pitt-Hopkins syndrome have distinctive facial features that include thin eyebrows, sunken eyes, a prominent nose with a high nasal bridge, a pronounced double curve of the upper lip (Cupid's bow), a wide mouth with full lips, and widely spaced teeth. The ears are usually thick and cup-shaped.

Children with Pitt-Hopkins syndrome typically have a happy, excitable demeanor with frequent smiling, laughter, and hand-flapping movements. However, they can also experience anxiety and behavioral problems.

Other features of Pitt-Hopkins syndrome may include constipation and other gastrointestinal problems, small hands and feet, a single crease across the palms of the hands, flat feet (pes planus), an unusually small head (microcephaly), nearsightedness (myopia), eyes that do not look in the same direction (strabismus), short stature, and minor brain abnormalities. Males with Pitt-Hopkins syndrome may have an unusually small penis or undescended testes (cryptorchidism).

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Pitt-Hopkins syndrome - Genetics Home Reference