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Opitz syndrome is characterised by the association of craniofacial anomalies (including hypertelorism with telecanthus, a wide nasal bridge, and sometimes cleft palate/ lip) genito-urineal abnormalities (with hypospadias in affected males) malformations of larynx, pharynx and/or trachea (causing difficulties to swallow and breathe) and, less frequently, other anomalies of the ventral midline. Intelligence may be normal but mild intellectual deficit may occur. Opitz syndrome was originally categorized as two distinct disorders: G syndrome and BBB syndrome (acronyms BBB and G represent the initials of the surnames of the originally reported families). It has since been determined that these disorders represent the same entity, termed Opitz G/BBB syndrome. Two forms of Opitz G/BBB syndrome can be distinguished: one with an autosomal dominant inheritance and the other with an X-linked inheritance. Mutations in the MID 1 gene (which encodes the midline 1 protein) are responsible for 80% of cases of the X-linked form. The exact pathogenesis remains unknown. Prenatal diagnosis is possible by ultrasonography. Multidisciplinary management must be adapted to each patient. Alternative feeding methods are often proposed in order to prevent aspiration, which can lead to serious complications. The prognosis depends on the degree of involvement, which varies greatly among individuals, even within the same family. |