Marshall-Smith Syndrome

Genetic disorder characterized by the association of facial dysmorphism, failure to thrive, and accelerated osseous maturation and linear growth. Accompanied by severe respiratory problems that are often fatal during the first year of life, mental retardation, hypotonia, muscle weakness, and psychomotor retardation. Craniofacial abnormalities include prominent forehead and eyes, maldevelopment of the epiglottis, and laryngomalacia.

First described in 1971 by Richard E. Marshall, an American pediatrician, and David W. Smith, an American pediatrician and dysmorphologist.

Rare; 25 cases described in the literature through 2000.

None; all cases reported were sporadic.

Unknown.

Based on clinical aspect and typical radiograph of bones: markedly advanced osseous maturation, widening of the middle and proximal phalanx, and multileveled platyspondylia (thin anterior part of vertebral bodies).

Orofacial dysmorphism: prominent forehead, shallow orbits with prominent eyes, megalocornea, micrognathia caused by hypoplastic mandibular ramus, upturned nose with anteverted nostrils, large overflexed ears. Stridor caused by laryngeal anomalies or hypoplasia with rudimentary epiglottis. Scoliosis. Atlantoaxial instability. Hypoplastic thorax. Choanal atresia and/or functional obstruction of the upper airway leading to sleep apnea. Mental retardation. Most patients die before age 2 years as a consequence of recurrent pulmonary infections (chronic aspiration).

Check for presence or history of stridor and/or laryngomalacia; probable sleep apnea syndrome: consider insertion of a nasopharyngeal airway before sleep during a few days before anesthesia; echocardiography to rule out associated cardiac malformation and pulmonary hypertension caused by chronic upper airway obstruction. Check patency of both nostrils. Cervical spine radiograph to check atlantoaxial stability. Chest radiograph to check for infection and hypoplasia.

Difficult face-mask ventilation. Direct laryngoscopy may be complicated by the presence of macroglossia, malformed epiglottis, and laryngomalacia. Difficult tracheal intubation should be anticipated. An induction technique maintaining spontaneous breathing is indicated; upper airway collapse at the beginning of induction and at awakening can be prevented by use of a nasopharyngeal airway; have laryngeal mask airway and fiberoptic bronchoscope ready for use.

McCune-Albright Syndrome: Fibrous dysplasia of bones associated with endocrine disorders, mainly precocious puberty.

Sotos Syndrome: Characterized by excessively rapid growth during the first year of life, acromegalic craniocerebral features (macrocephaly, prominent forehead), and a nonprogressive cerebral disorder with mental retardation. Other features include high-arched palate and prognathism with premature eruption of teeth, hypotonia, hyperthyroidism or hypothyroidism, delayed motor and cognitive development.

Weaver Syndrome: Syndrome characterized by accelerated maturation of bone and physical growth accompanied by developmental delay and specific facial abnormalities (micrognathia, hypertelorism, down-slanting of palpebral fissures), hypertonia, progressive spasticity, and a typical low-pitched and hoarse cry in infants.