Cephaloskeletal Dysplasia

A brachymelic primordial disproportionate dwarfism associated with facial dysmorphism and neurologic impairment.

Microcephalic Osteodysplastic Primordial Dwarfism, Type I and III (MOPD I and III); Brachymelic Primordial Dwarfism; Taybi-Linder Syndrome (MOPD I); Low-Birth-Weight Dwarfism with Skeletal Dysplasia.

Approximately 22 cases have been described. Autosomal recessive. Parental consanguinity has been reported for some cases.

Some features are shared with those of Seckel Syndrome, however, dwarfism in MOPD I and III is disproportionate. Type I is characterized by short and bowed long bones. Typical findings in type III include elongated clavicles, cleft cervical vertebral arches, lumbar platyspondyly, enlarged metaphyses, and marked dysplasia of the pelvis. However, MOPD type I and III now are accepted as variants of the same disease.

Severe intrauterine (with oligohydramnios) and postnatal growth retardation are almost always present. The disease may affect head and neck (microcephaly, closed anterior fontanelle at birth, prominent occiput, sloping forehead, low-set and dysplastic ears, large protruding eyes, strabismus, big, prominent nose, mandibular hypoplasia, high vaulted narrow palate, unilateral choanal atresia, short neck), the urogenital tract (micropenis, cryptorchidism, obstructive hydronephrosis), the skeleton (hip dislocation, joint flexion deformities, flexion contractures in the big joints, short limbs, brachydactyly, clinodactyly of the fifth digit, delayed bone age, abnormal vertebral size and shape [cervical clefts, platyspondyly], flared iliac wings, shallow acetabula, delayed metaphyseal maturation, bowed femurs and humeri) and the central nervous system (delayed psychomotor development, seizures, micrencephaly, corpus callosum agenesis, gyral anomalies, enlarged lateral ventricles, hypoplastic cerebellum and frontal lobes, agenesis of the cerebellar vermis, heterotopias). Other features include alopecia, dry skin, bilateral simian creases, and decreased sweating. Tetralogy of Fallot and renal leakage have been described in one case. This disease is generally lethal within the first year of life. The oldest survivor died at 6.5 years of age. The recorded causes of death are most often infections, such as meningitis, meconium peritonitis, aphthous stomatitis, sepsis, and airway infections with pneumonia.

Anesthesia in this condition has not been described. Renal function should be assessed if hydronephrosis is present. The features of the disease suggest that mask ventilation and direct laryngoscopy may be difficult. Given the possible anomalies of the cervical spine, tracheal intubation should be performed in a way that forced reclination of the head is avoided. Decreased sweating may lead to abnormal thermoregulation in the perioperative period. Joint contractures may make patient positioning difficult. Central neuraxial anesthesia is not contraindicated, but may be difficult secondary to anatomical anomalies and difficulties with positioning. Patients are predisposed to seizures. Avoid drugs that lower the seizure threshold. Anticonvulsant medications and renal failure may alter the metabolism and excretion of some anesthetic agents.

Cerebro-Oculo-Skeleto-Renal Syndrome: A congenital syndrome combining dwarfism and ocular, cerebral, and renal symptoms. Lethal in infancy.

Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) Type II: Approximately 20 cases have been described. Inheritance is autosomal recessive, with parental consanguinity being a causative factor in almost one third of the patients. Both sexes seem to be equally affected. Intrauterine and severe postnatal growth retardation with disproportionate dwarfism have been reported in almost all cases. Moderate mental retardation, microcephaly with a high forehead, dysplastic ears, prominent nose, mandibular hypoplasia, retarded ossification, narrow and high iliac wings, shallow acetabula, coxa vara, short and bowed humeri and femora, proximal femoral epiphyseolysis, enlarged metaphyses, metaphyseal flaring, triangular epiphyses, and clinodactyly are common findings. Occasionally, craniosynostosis, antimongoloid slanting of the palpebral fissures, and cryptorchidism can be diagnosed. Anomalies of inner organs appear not to be related to this syndrome, although one patient with hypoplasia of the anterior corpus callosum has been described. Anesthetic implications mainly arise from airway management, which may be difficult in the presence of mandibular hypoplasia. Positioning may be difficult secondary to the orthopedic features.

Seckel Syndrome: A form of primordial dwarfism with characteristic head shape (“bird-like") and pongidoid microcephaly (also called “chimpanzee brain"). Other features include large ears, sparse hair, joint defects, clubfoot, trident hands, mental retardation.