BAAT and vitamin deficiency disorder: Additionally, they were molecularly identified with 4 different types of pathogenic homozygous mutations in the BAAT gene, including a nonsense mutation c.58C>T (p.R20X) and 3 missense mutations c1156G>A (p.G386R), c.206A>T (p.D69V), and c.250C>A (p.P84T).[9] In a related study, Carlton et al reported on the case of Amish children who suffered from vitamin deficiency and failure to thrive.