A disorder that shares features with trisomy 18, but has a normal karyotype. The neurologic signs include severe hypotonia and psychomotor retardation and absent neonatal reflexes. Dysmorphic features and cardiac defects are present.
Bowen Syndrome of Multiple Malformations.
Six children from four families have been described, one case was associated with ☞Zellweger Syndrome.
Based on the clinical features. In contrast to Zellweger Syndrome, peroxisomes and liver and kidney function are considered to be normal in Bowen Syndrome and epiphyseal calcifications are not present.
These patients typically die within the first year of life (the mean age at death is approximately 3 months). The clinical findings can be quite variable, ie, not all the following findings will be present in any one patient. Neurologic signs may include severe muscular hypotonia and psychomotor retardation, absent tendon, abdominal, startle and withdrawal reflexes, agenesis of the corpus callosum, absent olfactory bulbs with partial arhinencephaly, and failure to thrive secondary to hypotonia with sucking and swallowing difficulties. The head has been described as “light-bulb”-shaped, referring to the high forehead with brachycephaly and persistence of the metopic suture. Closure of the anterior and posterior fontanelles may be delayed. Facial dysmorphic signs may consist of hypertelorism with hypoplastic supraorbital ridges, congenital glaucoma with corneal clouding, nystagmus, cataract, low-set, dysplastic and posteriorly rotated ears, short “saddle” nose, micrognathia, and high arched palate. Skeletal anomalies are present and include contractures (elbow, fingers, knees), cubiti valga, camptodactyly and superposition of fingers, “rocker-bottom” feet or talipes equinovarus. Cardiac defects such as patent ductus arteriosus, atrial or ventricular septal defects, partial anomalous venous drainage, and aortic abnormalities may be present. Abnormally short trachea with high carina and abnormal lung segmentation/agenesis of lung lobes have been reported. Urogenital anomalies such as enlarged clitoris (in all affected girls), hypospadias and hydroureter have been described. Ventral hernia or omphalocele may be present.
Precautions before anesthesia
These patients are unlikely to present for major surgery due to the dismal prognosis. However, the usually severe psychomotor delay associated with feeding difficulties may require the insertion of a gastrostomy tube, which often can be achieved with generous infiltration of the abdominal wall with local anesthetics supplemented with intravenous ketamine or low dose inhalational anesthetics by mask if required. However, if swallowing is difficult, then the risk of aspiration is most likely increased and the same applies if insufflation the stomach is required for the procedure, thus endotracheal intubation will be the safer option. Review or obtain an echocardiography exam to rule out or confirm the presence of congenital cardiac defects.