Six cases of Williams syndrome were analyzed revealing diverse and non-specific prenatal manifestations, with all cases showing deletions in the 7q11.23 region ranging from 0.75 Mb to 1.59 Mb, and the authors conclude that prenatal genetic testing should be recommended for cases with fetal growth retardation, cardiac structural abnormalities, and high-risk NIPT results.
All six Williams syndrome cases had deletions in the 7q11.23 region, with sizes ranging from 0.75 Mb to 1.59 Mb.
Prenatal diagnostic indications for Williams syndrome were diverse across the six cases.
Family verification revealed that two deletions were maternally inherited, one was de novo, and three cases had parental verification refused.
A postnatally diagnosed child carried a de novo 1.43 Mb deletion and presented with global developmental delay, dysmorphic facial features, and complex cardiac malformations.
The prenatal manifestations of Williams syndrome are described as diverse and non-specific.
This research describes six cases of Williams syndrome (WS), a genetic condition caused by a missing piece of chromosome 7, diagnosed at a hospital in Hubei Province, China between 2023 and 2025. All six patients were found to be missing a segment of chromosome 7 in a region called 7q11.23, with the missing piece varying in size from 0.75 to 1.59 million base pairs of DNA. The reasons that led doctors to investigate for a genetic condition before birth were quite varied and included findings such as enlarged brain ventricles, a heart vessel abnormality, intestinal blockage, poor fetal growth in a previous pregnancy, and an abnormal result on a prenatal blood screening test. The study also examined where the genetic deletions came from. In two cases, the missing chromosome segment was inherited from the mother, and in one case it appeared newly in the child (called 'de novo'). Three families declined to undergo testing to determine the origin. One child was diagnosed after birth and had a newly occurring deletion along with developmental delays, distinctive facial features, and complex heart defects — features characteristic of Williams syndrome. This research suggests that the signs of Williams syndrome detectable before birth are highly variable and not specific to just one type of abnormality, making prenatal identification challenging. The authors highlight that when ultrasound shows fetal heart defects or poor growth, or when a prenatal blood screening test raises concern, genetic testing should be considered. Advanced genetic tests — including chromosomal microarray analysis, copy number variation sequencing, and whole exome sequencing — can provide detailed information useful for managing affected children individually. Testing parents can also clarify whether the condition might recur in future pregnancies, which has important implications for family planning.
Liu X, Wang X, Sun D, Li Q, Liu J, Huang P. (2026). [Analysis of the prenatal and postnatal clinical features of six cases of Williams syndrome and a literature review].. Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics. https://doi.org/10.3760/cma.j.cn511374-20260327-00148