Indeed, mutations in the human TBX3 lead to ulnar mammary syndrome which is characterized by several clinical malformations including hypoplasia of the mammary and apocrine glands, defects of the upper limb, areola, dental structures, heart and genitalia.
Increasing evidence demonstrates that dysfunctional TBX2 and TBX3 result in outflow tract malformations, implying that both of them are involved in CTD pathogenesis.
We report on a combination of congenital malformations in a mother and her fetus harboring a heterozygous deletion encompassing the TBX5 and TBX3 genes, which are disease-causing in Holt-Oram and ulnar-mammary syndromes, respectively.
The possibility that mechanisms in addition to TBX3 haploinsufficiency may cause UMS or other malformations merits investigation in the human UMS population.
Mutations of TBX3 cause ulnar-mammary syndrome (MIM 181450) in humans, an autosomal dominant disorder characterized by the absence or underdevelopment of the mammary glands and other congenital anomalies.