Clark-Baraitser syndrome
Overview
A very rare syndrome characterized mainly by tallness, large head, mental retardation and various facial anomalies.
Symptoms
* Tall stature * Large head * Mental retardation * Square forehead * Prominent eyebrows * Broad nasal tip * Prominent lower lip * Large ears * Obesity * Enlarged testes * Large hands * Gap in front teeth
Causes
* Constitutional tall stature –Most common cause o Endocrine disorders –Excess GH secretion (pituitary gigantism) –McCune-Albright syndrome –Multiple endocrine neoplasia is associated with excess GH secretion * Precocious puberty –Tall initially –Final height compromised * Hyperthyroidism * Reduced sex steroid activity –Hypogonadism –Klinefelter syndrome –Androgen or estrogen deficiency –Estrogen resistance –Androgen insensitivity syndrome * Excess insulin –Exogenous obesity –Maternal diabetes mellitus * Cerebral gigantism (Sotos syndrome) * Weaver syndrome * Beckwith-Wiedemann syndrome * Marfan syndrome * Homocystinuria * Fragile X syndrome
Treatment
* Constitutional and syndromic tall stature –For predicted adult height >3 SD above the mean, or evidence of significant psychosocial impairment –High-dose sex steroids to induce earlier growth plate closure –Treatment is controversial * Pituitary adenoma –Transphenoidal surgery is treatment of choice –Postoperative GH and IGF-I define a biochemical cure –Pituitary radiation if case surgery does not normalize GH secretion –Medical therapy: Somatostatin analogs, dopamine agonists, GH antagonists (GH-receptor inhibitor), for suppressing IGF-I and GH