Ulnar-mammary syndrome (UMS) is an autosomal dominant disorder resulting from TBX3 haploinsufficiency. It typically affects limb, apocrine gland, hair, tooth and genital development and shows marked intrafamilial and interfamilial variability in phenotypic expression. We report a family (twin brothers and their father) affected with UMS because of a novel TBX3 mutation. The twin brothers showed classical features of UMS, whereas their father was mildly affected. The c.1423C>T (p.Q475*) nonsense mutation in exon 6 of the TBX3 gene identified in the patients by targeted Sanger sequencing is predicted to lead to premature termination of translation. This is the first report of a Cypriot family with UMS resulting from a novel TBX3 mutation. This report provides additional evidence in support of the rich variability in phenotypic expression, the mutational heterogeneity and ethnic diversity associated with this rare condition.

中文翻译：

---

尺骨-乳腺综合症的塞浦路斯血统家族中的新TBX​​3突变。

尺乳综合症（UMS）是由TBX3单倍剂量不足引起的常染色体显性遗传疾病。它通常会影响肢体，顶泌腺，头发，牙齿和生殖器的发育，并在表型表达中显示出明显的家族内和家族间变异性。我们报告了由于新的TBX3突变而受UMS影响的家庭（双胞胎兄弟和他们的父亲）。这对双胞胎兄弟表现出UMS的经典特征，而他们的父亲则受到了轻微的影响。通过靶向Sanger测序在患者中鉴定出的TBX3基因外显子6中的c.1423C> T（p.Q475 *）无意义突变预计会导致翻译的过早终止。这是由新的TBX3突变引起的带有UMS的塞浦路斯家族的首次报道。该报告提供了其他证据来支持表型表达的丰富变异性，