Clinical findings and molecular cytogenetic characterization of 19q13.42 microduplication: three cases report and literature review

Abstract BackgroundTrisomy 19q is a recognizable syndrome and associated with a wide spectrum of clinical phenotypes in clinic. The purpose of this study was to explore the prenatal phenotypes of 19q13.42 duplication, which was rarely reported in clinic. Case presentationThree pregnant women presenting diverse indications for prenatal diagnosis accepted amniocentesis: increased nuchal translucency (case 2) and high risk of trisomy 21 (case 1 and case 3). Case 1 and case 2 shared similar duplicated locus in the region of 19q13.42, encompassing part NLRP12 gene. Case 2 inherited the chromosomal duplication from the mother with normal phenotypes. Case 3 carried a 1.445Mb duplication in the 19q13.42q13.43 region. It was proposed that evolutionary duplication of NLRP12 gene could have a causative role in autoinflammatory diseases development. The genotype-phenotype correlation depends mainly on the duplicated size and functional genes involved, which is still yet to be determined. All pregnant women chose to continue the pregnancy and delivered healthy children with no apparent abnormalities.ConclusionsThe 19q13.42 microduplications in our study are the smallest fragments compared to previous literature. We delineated 19q duplication cases without structural ultrasound anomalies for the first time, which enriched the prenatal phenotypes of this chromosomal aberration. It was proposed that long term follow up analysis should be guaranteed till adulthood to determine whether there will be other emerging clinical symptoms and developmental-behavioral disorders for such carriers.