Clin Lab. 2024 Oct 1;70(10). doi: 10.7754/Clin.Lab.2024.240517.
Thalassemia is a common monogenic disorder, and children with β-thalassemia major require regular blood transfusions and iron removal therapy. Klinefelter syndrome (KS) is a common sex chromosome abnormality, and 48,XXYY is rare. This report is the first to describe a fetus with a karyotype of 48,XXYY in prenatal diagnosis of β-thalassemia major.
Amniotic fluid was collected by puncture for the prenatal diagnosis of thalassemia, and chromosomal karyotyping was also performed. PCR and reverse dot-blot hybridization (PCR-RDB) were used to identify 17 common β-thalassemia mutations in China. Karyotype analysis of amniotic fluid was performed.
The results of PCR-RDB revealed that the genotype of the fetus was a homozygote of CDs41-42 (-TTCT) in the HBB gene. The karyotype analysis displayed that the fetus had Klinefelter syndrome (KS), and the karyotype was the rare 48,XXYY. The fetus was diagnosed with β-thalassemia major and KS.
An unexpected detection of the rare 48,XXYY in the prenatal diagnosis of a fetus with β-thalassemia major. There is a pitfall of genetic counseling and prenatal diagnosis in China.
地中海贫血是一种常见的单基因疾病，重型β地中海贫血患儿需要定期输血和铁去除治疗。克氏综合征（KS）是一种常见的性染色体异常，而 48,XXYY 则较为罕见。本报告首次描述了产前诊断重型β地中海贫血胎儿中存在 48,XXYY 核型。
经穿刺采集羊水进行地中海贫血产前诊断，并进行染色体核型分析。采用聚合酶链反应（PCR）和反向点杂交（PCR-RDB）技术对中国常见的 17 种β地中海贫血基因突变进行鉴定。对羊水进行核型分析。
PCR-RDB 结果显示，胎儿的基因型为 HBB 基因中的 CD41-42（-TTCT）纯合子。核型分析显示胎儿患有克氏综合征（KS），核型为罕见的 48,XXYY。该胎儿被诊断为重型β地中海贫血和 KS。
在重型β地中海贫血胎儿的产前诊断中意外发现了罕见的 48,XXYY。这在中国的遗传咨询和产前诊断中存在一个陷阱。
