A clinical diagnosis of Martsolf syndrome was made and he had a negative screen for RAB3GAP1, RAB3GAP2, RAB18 and TBC1D20. His elder brother, two maternal uncles and a maternal aunt all had a very similar pattern of problems (Table 2) and all had died in early childhood with evidence of cardiac failure[18]. Here, RAB3GAP1 is linked to Martsolf syndrome.