Gentile M, Volpe P, Cariola F, Di Carlo A, Marotta V, Buonadonna AL, Boscia FM. Prenatal diagnosis of chromosome 4 mosaicism: Prognostic role of cytogenetic, molecular, and ultrasound/MRI characterization.
Am J Med Genet A 2005;
136:66-70. [PMID:
15940687 DOI:
10.1002/ajmg.a.30506]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Trisomy 4 mosaicism is extremely rare: herein we report the cytogenetic and molecular characterization and prenatal US findings of a case diagnosed prenatally. The diagnosis of level III mosaicism was established in cultured amniotic fluid cells (22.5%). At 22 weeks gestation, micrognathia and hypotelorism were suspected at 2-D sonography, and confirmed at 3-D examination. In addition, 2-D US showed cerebellar hypoplasia associated with borderline ventriculomegaly (confirmed at magnetic resonance imaging, MRI), spine deformity (hemivertebra), and a complete atrioventricular septal defect (AVSD). The pregnancy was terminated. Trisomy 4 mosaicism was confirmed in placental and fetal skin cultured cells. The cord blood karyotype was normal. Molecular analysis excluded uniparental disomy of chromosome 4, and indicated that the trisomy 4 was of maternal meiotic origin. In presence of chromosome 4 mosaicism, accurate fetal sonography and echocardiography are mandatory. Low level mosaicism and normal echographic examinations seem to be associated with good prognosis. In postnatal life, chromosome 4 mosaicism should be suspected, and cytogenetic analysis proposed of further tissues (i.e., skin), in presence of craniofacial dysmorphism, cardiac defects, and abnormal hands/feet, even if mental development is appropriate or only slightly impaired.
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