A form of dwarfism characterized by short limbs with abnormal morphogenesis of the face and external genitalia.
Costovertebral Segmentation Defect with Mesomelia (COVESDEM) Syndrome; Robinow Dwarfism; Fetal Face Syndrome; Acral Dysostosis with Facial and Genital Abnormalities Syndrome.
Initially described by Meinhard Robinow, a German-American geneticist, in 1969.
Very rare, less than 200 cases reported.
Autosomal recessive but autosomal dominant forms exist.
The recessive forms (also Costovertebral Segmentation Defect with Mesomelia [COVESDEM] Syndrome) are caused by mutation in the ROR2 gene located on 9q22 (allelic to brachydactyly type B) and are more severe. Autosomal dominant forms are due to mutations of WNT5A on chromosome 3p14.3.
Characteristic facial features include macrocephaly; dolichocephaly; bulging forehead; micrognathia; hypertelorism; wide palpebral fissures; S-shaped lower eyelids; down-slanting palpebral fissures; short, upturned nose with anteverted nostrils and long philtrum; V-shaped or tented upper lip; triangular mouth; crowded teeth; gingival enlargement; and ankyloglossia. They are combined with mesomelic shortening of the forearm and hypoplastic genitalia.
Features can also involve head and neck (large anterior fontanel, posteriorly rotated ears, absent uvula, crowded teeth, prominent eyes), heart (right ventricular outlet obstruction), genitourinary (renal duplication, hydronephrosis, small penis, small clitoris, small labia majora), gastrointestinal (GI) (abnormal umbilicus, umbilical hernia cryptorchism), and skeleton (scoliosis, ribcage, hand and foot abnormalities, small stature, developmental delay). The main discriminating feature is the occurrence of multiple rib and vertebral anomalies in the recessive form.
Precautions before anesthesia
Evaluate cardiac function (clinical, ECG, echocardiography, radionuclide imaging, and cardiac catheterization if necessary); renal function (clinical, echography, laboratory); airway (clinical, radiographs); and respiratory function if scoliosis is important (clinical, chest radiographs, pulmonary function test, arterial blood gas analysis).
Direct laryngoscopy and tracheal intubation can be difficult. Spontaneous respiration must be maintained until the airway is secured and ventilation is confirmed. Tracheal intubation can be difficult. A laryngeal mask and fiberoptic equipment for tracheal intubation may be required. Perioperative cardiac and respiratory monitoring should be considered. Careful intraoperative positioning is needed because of skeletal anomalies. Regional anesthesia is not contraindicated; however, the presence of vertebral anomalies should be considered and prior imaging of the spine recommended.
Fluid regimen and anesthetic drugs should be adapted to renal function. Muscle relaxants should be avoided until airway is secured and ventilation is confirmed.
et al: Specific genetic diseases at risk for sedation/anesthesia complications. ...