Medical Genetics Unit, A.O.R.N. "G. Rummo", Benevento, Italy.
Department of Translational Medical Science - Section of Pediatrics, Azienda Ospedaliera Universitaria Federico II, Naples, Italy.
Clin Genet. 2019 Feb;95(2):253-261. doi: 10.1111/cge.13127. Epub 2018 Jan 25.
The Say-Barber-Biesecker-Young-Simpson variant of Ohdo syndrome (SBBYSS) and Genitopatellar syndrome (GTPTS) are 2 rare but clinically well-described diseases caused by de novo heterozygous sequence variants in the KAT6B gene. Both phenotypes are characterized by significant global developmental delay/intellectual disability, hypotonia, genital abnormalities, and patellar hypoplasia/agenesis. In addition, congenital heart defects, dental abnormalities, hearing loss, and thyroid anomalies are common to both phenotypes. This broad clinical overlap led some authors to propose the concept of KAT6B spectrum disorders. On the other hand, some clinical features could help to differentiate the 2 disorders. Furthermore, it is possible to establish a genotype-phenotype correlation when considering the position of the sequence variant along the gene, supporting the notion of the 2 disorders as really distinct entities.
Say-Barber-Biesecker-Young-Simpson 变异型 Ohdo 综合征（SBBYSS）和 Genitopatellar 综合征（GTPTS）是由 KAT6B 基因中从头出现的杂合序列变异引起的 2 种罕见但临床描述良好的疾病。这 2 种表型的特征均为显著的全面发育迟缓/智力残疾、低张力、生殖器异常和髌骨发育不良/缺失。此外，先天性心脏缺陷、牙齿异常、听力损失和甲状腺异常在这 2 种表型中均很常见。这种广泛的临床重叠导致一些作者提出 KAT6B 谱障碍的概念。另一方面，一些临床特征有助于区分这 2 种疾病。此外，当考虑序列变异在基因中的位置时，可以建立基因型-表型相关性，支持这 2 种疾病是真正不同的实体的观点。
