Marshall-Smith syndrome is a rare genetic disease characterized by tall stature and advanced bone age at birth. The prevalence is unknown but around 30 cases have been reported in the literature. The disorder associates several dysmorphic signs, including prominent forehead, bulging eyes, blue sclerae, anterversed nostrils and micrognathia. Clinical symptoms are severe with feeding difficulties, failure to thrive and a strong tendency to contract respiratory infections. X-rays show advanced bone age and short and conical phalanges. The cause of this disease remains unknown, but its sporadic occurrence suggests a de novo dominant mutation. Diagnosis depends on close examination of the clinical findings and X-ray examinations. Differential diagnosis should include Weaver syndrome and Sotos syndrome, which share similar skeletal findings but are not associated with recurrent respiratory infections or characteristic facies. There is no specific treatment for the syndrome. Malnutrition and respiratory infections should be treated symptomatically. The prognosis is poor and the disorder is usually fatal within the first years of life. A few cases of prolonged survival have been reported in patients without respiratory complications and are associated with intellectual deficit.
Last update: July 2006