Uniparental disomy and prenatal phenotype
نویسندگان
چکیده
RATIONALE Uniparental disomy (UPD) gives a description of the inheritance of both homologues of a chromosome pair from the same parent. The consequences of UPD depend on the specific chromosome/segment involved and its parental origin. PATIENT CONCERNS We report prenatal phenotypes of 2 rare cases of UPD. DIAGNOSES The prenatal phenotype of case 1 included sonographic markers such as enlarged nuchal translucency (NT), absent nasal bone, short femur and humerus length, and several structural malformations involving Dandy-Walker malformation and congenital heart defects. The prenatal phenotype of Case 2 are sonographic markers, including enlarged NT, thickened nuchal fold, ascites, and polyhydramnios without apparent structural malformations. INTERVENTIONS Conventional G-band karyotype appears normal in case 1, while it shows normal chromosomes with a small supernumerary marker chromosome (sSMC) in case 2. Genetic etiology was left unknown until single-nucleotide polymorphism-based array (SNP-array) was performed, and segmental paternal UPD 22 was identified in case 1 and segmental paternal UPD 14 was found in case 2. OUTCOMES The parents of case 1 chose termination of pregnancy. The neonate of case 2 was born prematurely with a bellshaped small thorax and died within a day. LESSONS UPD cases are rare and the phenotypes are different, which depend on the origin and affected chromosomal part. If a fetus shows multiple anomalies that cannot be attributed to a common aneuploidy or a genetic syndrome, or manifests some features possibly related to an UPD syndrome, such as detection of sSMC, SNP-array should be considered.
منابع مشابه
Case report: uniparental disomy 16 in association with congenital heart disease.
Uniparental disomy (UPD) is the inheritance of both copies of a given chromosome from the same parent (Warburton, 1988; Anon., 1991). The exact disease associations of UPD of individual chromosomes have yet to be fully elucidated and the question of whether UPD of some chromosomes may be regarded as a benign finding remains unanswered. We report an infant with uniparental maternal disomy 16, th...
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