Hypotonia, ataxia, developmental delay and tooth enamel defect syndrome (HADDTS; MIM: 617915) secondary to a recurrent de novo missense mutation in CTBP1 [NM_001012614.1:c.991C>T, p.(Arg331Trp)] was first reported by Beck et al.3They described four unrelated individuals with a neurodevelopmental phenotype consisting of early onset developmental delay, intellectual impairment, hypotonia, cerebellar dysfunction, poor weight gain, tooth enamel defects and variable changes on muscle biopsy.3 This evidence concerns the gene CTBP1 and Global developmental delay.