Discussion
With the development of genetic technology, more and more genetic diseases have been diagnosed. So far, more than 83 WDSTS patients have confirmed KMT2A gene mutations, most of which share similar clinical features, such as elbow or back hirsutism, growth retardation, cognitive impairment, prenatal and postnatal growth retardation and unique The appearance of the face: eyelid cracks, downward slope, wide nose bridge, wide nose, long eyelashes, thick eyebrows[3; 15]. In addition to low muscle tone, peculiar facial features, and intellectual disability, the frameshift mutation we discovered also has a new feature: early teething, fast tooth replacement, and dysplasia of axons.
There are currently more than 20 papers reporting new mutations in the KMT2A gene. The Clinvar database reports nearly 100 mutations and small indels[3; 20], classified as pathogenic, of which 43 are frameshift small indels, 39 are missense mutations and 4 are splicing mutations, nearly 60% are located in exons 3 and 27 mutations[5]. The mutation in this case is also located in exon 3.
Genetic diseases have experienced long-term socio-psychological and economic burdens. Benefiting from the development of genetic technology, WES not only has a higher genetic diagnosis rate, but also considerable cost savings. The diagnostic cost of WES is getting lower and lower. Perhaps the use of WES for prenatal diagnosis is an economically feasible and effective means to reduce birth defects caused by genetic mutations.
CONCLUSION To our knowledge, this is a new mutation that causes the child’s intellectual disability, but the parents do not have this gene mutation. In summary, our findings extend the WDSTS genetic and phenotypic spectrum.DATA AVAIL ABILITY STATEMENT The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.
Ethics statement
Written informed consent has been obtained from the minor’s parents, and all the data in the article have been approved.