Extremely rare syndrome combining congenital heart defects with a Dandy-Walker–like malformation and craniofacial malformations.
3C Syndrome (Cranio-Cerebello-Cardiac Dysplasia Syndrome); Dandy-Walker–like Malformation with Atrioventricular Septal Defect Syndrome; Del 6p25 Syndrome.
Congenital genetic disorder first reported by D. Ritscher and A. Schinzel in 1987.
Very rare (less than 50 cases worldwide). It seems to be more frequent in Canadian Native Americans.
Caused by homozygous mutation in the KIAA0196 gene on chromosome 8q24 and/or an environmental teratogen.
Clinically evocated by the association of cardiac malformations, cerebellar hypoplasia, and cranial dysmorphism. The association with immunoglobulin deficiency (IgG2 and IgG4) was reported in one patient. Chest radiographs may show multiple ossification defects.
Clinical features include head (macrocephaly, hypertelorism, prominent forehead and occiput, down-slanting palpebral fissure, depressed nasal bridge, low-set ears, narrow palate, short neck), central nervous system (hydrocephalus, hypoplastic cerebellar vermis, posterior fossa cyst/dilated fourth ventricle [Dandy-Walker malformation], cranial nerve palsies, nystagmus, truncal ataxia, and mild-to-moderate growth and psychomotor retardation), heart (wide range of anomalies from complete/partial atrioventricular canal defects, tetralogy of Fallot, double-outlet right ventricle, atrial septal defect, ventricular septal defect), and skeleton (first rib aplasia, camptodactyly of fingers, hip dislocation, hemivertebra, hypoplasia of terminal phalanges, micronychia). Other clinical signs include hypospadias, coloboma of the iris and/or retina, congenital glaucoma, optic nerve atrophy, malrotation of the gut, anal atresia, hydronephrosis, and immunodeficiency.
Precautions before anesthesia
It is recommended to review carefully the neurological history (motor/mental milestones) and any complications that might have happened during the administration of previous anesthesia. Assess neurological function, particularly the cranial nerves and the cerebellar function. Also, the potential for raised intracranial pressure (clinical, electroencephalogram [EEG], computed tomography [CT] scan) must be carefully evaluated. A complete cardiac evaluation, including ECG, chest radiographs, echocardiogram, and cardiac catheterization is highly suggested because of several reports of early death due to the severity of the cardiac defect. Assess airway for difficulty with ventilation and tracheal intubation.
Techniques should be tailored according to the cardiac defect present and the surgical procedure planned. Antibiotic prophylaxis for endocarditis and prevention of air embolism with adequate intravascular hydration are mandatory. Patient may be uncooperative as a consequence of mild mental retardation. Difficult airway may be anticipated with abnormal facial appearance, enlarged occiput, and short neck. Possible risk of pulmonary aspiration must be kept in mind. The presence of cranial nerve palsy increases the risk. Caution must be used with supraclavicular brachial nerve block because of the possible aplasia of the first ...