title: A Fetus with Hb Bart's Disease Due to Maternal Uniparental Disomy for Chromosome 16.
abstract: We here report an unusual case of Hb Bart's (γ4) disease. Thalassemia screening of a couple showed that the wife was an α(0)-thalassemia (α(0)-thal) carrier and her husband's mean corpuscular volume (MCV) was normal. Chorionic villus sampling (CVS) was performed at 13 weeks' gestation for positive Down syndrome screening and chromosomal study of the cultured CVS showed a normal karyotype. Ultrasound examination at 22 weeks' gestation showed fetal cardiomegaly and raised middle cerebral artery peak systolic velocity. Cordocentesis confirmed fetal anemia and showed Hb Bart's disease. Multiplex gap-polymerase chain reaction (gap-PCR) for α-thal deletions on DNA extracted from the CVS showed the presence of a homozygous α(0)-thal - -(SEA) (Southeast Asian) deletion. The husband was found to be a carrier of the α(+)-thal -α(3.7) (rightward) deletion. Non paternity was excluded by fluorescent PCR using short tandem repeat (STR) markers on chromosomes 13, 18 and 21. A de novo terminal deletion of chromosome 16 was excluded by array comparative genomic hybridization (aCGH). Detection of uniparental disomy (UPD), using STR markers on chromosome 16 showed maternal uniparental isodisomy from 16pter to 16p13.2, and uniparental heterodisomy from 16p13.13 to 16qter.
authors.affiliation: a Department of Obstetrics & Gynaecology , Queen Mary Hospital , Hong Kong SAR , People's Republic of China.
authors.forename: Patrick K C
authors.initials: PK
authors.lastname: Au
authors.affiliation: a Department of Obstetrics & Gynaecology , Queen Mary Hospital , Hong Kong SAR , People's Republic of China.|b Department of Obstetrics & Gynaecology , The University of Hong Kong , Hong Kong SAR , People's Republic of China.
authors.forename: Anita S Y
authors.initials: AS
authors.lastname: Kan
authors.affiliation: a Department of Obstetrics & Gynaecology , Queen Mary Hospital , Hong Kong SAR , People's Republic of China.|b Department of Obstetrics & Gynaecology , The University of Hong Kong , Hong Kong SAR , People's Republic of China.
authors.forename: Mary H Y
authors.initials: MH
authors.lastname: Tang
authors.affiliation: c Department of Obstetrics & Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China.
authors.forename: Kwok Y
authors.initials: KY
authors.lastname: Leung
authors.affiliation: a Department of Obstetrics & Gynaecology , Queen Mary Hospital , Hong Kong SAR , People's Republic of China.|b Department of Obstetrics & Gynaecology , The University of Hong Kong , Hong Kong SAR , People's Republic of China.
authors.forename: Kelvin Y K
authors.initials: KY
authors.lastname: Chan
authors.affiliation: b Department of Obstetrics & Gynaecology , The University of Hong Kong , Hong Kong SAR , People's Republic of China.
authors.forename: Tommy W F
authors.initials: TW
authors.lastname: Tang
authors.affiliation: a Department of Obstetrics & Gynaecology , Queen Mary Hospital , Hong Kong SAR , People's Republic of China.|b Department of Obstetrics & Gynaecology , The University of Hong Kong , Hong Kong SAR , People's Republic of China.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Lau
mesh_terms: D000328:Adult; D000740:Anemia / Q000175:diagnosis* / Q000235:genetics; D015193:Chorionic Villi Sampling; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D017218:Cordocentesis; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D017384:Sequence Deletion; D024182:Uniparental Disomy / Q000235:genetics*; D017085:alpha-Thalassemia / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; C030448:hemoglobin Bart's
keywords: Hb Bart’s (γ4) disease; prenatal diagnosis (PND); thalassemia; uniparental disomy (UPD)