A frequently lethal neonatal syndrome characterized by chondrodystrophy, micromelic dyssegmental dwarfism, vertebral and metaphyseal abnormalities, advanced carpotarsal ossification, dislocation of the patellae and hips, glaucoma, and mental deficiency. Prognosis is poor.
Dyssegmental Dwarfism Rolland-Desbuquois Type; Dyssegmental Dysplasia Rolland-Desbuquois Type; Anisospondylic Campto-Micro-Melic Dwarfism.
Very rare, around 20 cases reported worldwide.
Evidence for heparan sulphate perlecan gene 2 (HSPG2) mutations on chromosome 1p36.12, which encodes perlecan. Perlecan binds to basement membrane proteins such as collagen IV and laminin-1. This may be responsible for increased cross-linking and abnormal collagen stiffness.
Clinical features (micromelia, limited joint mobility associated with cardiac and neurological anomalies) and radiological features (symmetrical short extremities, shortened trunk length, and narrow thorax). Gel electrophoresis shows abnormal collagen pattern.
Clinical features can involve skeleton (short, thick, bowed long bones; marked metaphyseal flaring and cupping; abnormal vertebrae with different sizes, thicknesses, and widths that may consist of two or more separate ossified masses; narrow thorax with horizontal ribs; reduced joint motility) and CNS (hydrocephalus, occipital encephalocele). Other occasionally reported features include hydronephrosis, hypertrichosis, and congenital heart defect in one case. In severe cases (also classified as Silverman-Handmarker Syndrome), death usually occurs within few days or weeks of birth. Even in milder form, survival beyond the first year of life is rare. Cause of death is usually respiratory related.
Precautions before anesthesia
Evaluate the airway for potential difficult tracheal intubation (clinical, radiographs). Assess respiratory function (clinical, chest radiograph, arterial blood gas), oxygen, and ventilatory requirement. Assess neurological status, which might include clinical and CT scan for possible hydrocephalus and raised intracranial pressure.
The potential for difficult airway management is present because of the flat face, small mouth, and short neck. There is a significant risk for difficult lung ventilation because of the narrow thorax and poor lung compliance. The requirement for postoperative ventilatory monitoring or support may be indicated. Intravenous access may be difficult because of the skin condition. Poor joint motility may be prone to pressure necrosis and require careful intraoperative positioning.
Muscle relaxants should be avoided until airway is secured and lung ventilation is confirmed. Prophylactic antibiotics are indicated in case of cardiopathy. Opioids should be used carefully because of the increased respiratory risk. Avoid succinylcholine in the presence of glaucoma.
Other conditions to be considered