A Chinese family with Noonan syndrome caused by a heterozygous variant in LZTR1: a case report and literature review

BackgroundNoonan syndrome is an inherited disease involving multiple systems. More than 15 related genes have been discovered, among whichLZTR1was discovered recently. However, the pathogenesis and inheritance pattern ofLZTR1in Noonan syndrome have not yet been elucidated.Case presentationWe herein describe a family withLZTR1-related Noonan syndrome. In our study, the proband, sister, mother, maternal aunt and grandmother and female cousin showed the typical or atypical features of Noonan syndrome. Only 3 patients underwent the whole-exome sequencing analysis and results showed that the proband as well as her sister inherited the same heterozygousLZTR1variant (c.1149 + 1G > T) from their affected mother. Moreover, the proband accompanied by growth hormone deficiency without other associated variants.ConclusionIn a Chinese family with Noonan syndrome, we find that the c.1149 + 1G > T variant inLZTR1gene shows a different autosomal dominant inheritance from previous reports, which changes our understanding of its inheritance and improves our understanding of Noonan syndrome.