Beemer-Langer Syndrome

At a glance

Genetic disorder characterized by multiple skeletal (and other) anomalies and death either in utero or in the early neonatal period as a result of respiratory failure.

Synonyms

Beemer-Langer Type Short Rib-Polydactyly Syndrome; Short Rib-Polydactyly Syndrome Type IV; SRPS Type IV; Polydactyly with Neonatal Chondrodystrophy, Type IV. Short-Rib Thoracic Dysplasia 12.

Incidence

Approximately 30 cases have been described.

Genetic inheritance

Autosomal recessive. The syndrome has been linked to a variety of genetic mutations, including an inversion on chromosome 17q21 or 17q23, an unbalanced translocation involving chromosome 6 and 22, and a balanced pericentric inversion on chromosome 4. Most karyotypes, however, are normal. Recent research considers this group of short-rib polydactyly phenotypes a ciliopathy and one of the genes most likely involved is IFT122 (Intraflagellar Transport 122) on chromosome 3q21.3-q22.1, encoding for protein complexes involved in retro- and anterograde transport along the ciliary axoneme, thus responsible for biogenesis and maintenance of the primary cilium.

Diagnosis

Based on the clinical picture and family history.

Clinical aspects

Most children are either stillborn or die in early infancy as a result of respiratory insufficiency secondary to pulmonary hypoplasia. Short tubular bones with severe limb shortness (micromelia) and smooth metaphyseal margins, macrocephaly, and perinatal hydrops with ascites affect almost all of these children. Other craniofacial findings may include central nervous system anomalies (eg, hydrocephalus with Dandy-Walker malformation, holoprosencephaly, agenesis/hypoplasia of the corpus callosum, cerebellar hypoplasia, hypothalamic hamartoblastoma), high and prominent forehead, flat face, small, low-set and posteriorly rotated dysplastic ears with undeveloped or overfolded helices, hypertelorism, epicanthal folds, short nose with depressed and wide nasal bridge, long philtrum, micrognathia, median cleft lip or tongue with or without cleft palate, grooved palate with thick palatine and alveolar ridges, small tongue, accessory frenula, facial milia around the nose, mouth, chin and ears, and a short and webbed neck. Craniosynostosis has occasionally been reported. The chest is hypoplastic with extremely short and horizontal ribs, highly positioned, thin clavicles (due to thoracic lordosis) and severe pulmonary hypoplasia. The abdomen is protuberant/distended. Congenital heart disease (eg, transposition of the great arteries, atresia of the ascending aorta, preductal coarctation of the aorta, ventricular septal defect), gastrointestinal (hypoplastic intrahepatic bile ducts, accessory spleen, unfixed mesentery with intestinal malrotation, short intestines, pancreatic ectopy or fibrosis, omphalocele) and urogenital abnormalities (renal dysplasia, focally persistent nephrogenic zone, small cortical cysts involving the glomeruli and tubules, polypoidal hypertrophy of the bladder urothelium, ambiguous genitalia) are frequently found. Additional skeletal anomalies may include small scapulae, platyspondyly, bowing of the radii and ulnae, iliac narrowing, trident aspect of the acetabular roof, hypoplastic fibulae (shorter than tibiae), talipes equinovarus, brachy-, syn- and occasional postaxial polydactyly.

Precautions before anesthesia

Due to the ...