Congenital heart defects (CHDs) are a group of structural abnormalities of the heart that have a combined incidence of approximately 1% in humans. It is estimated that 4–5% of CHDs are associated with chromosome abnormalities, 1–2% are associated with single gene syndromes, and 1–2% are due to known teratogens, with the rest presumably determined in a multifactorial fashion.1 Conotruncal heart defects (CTHD) represent 15–20% of CHDs.2 CTHDs share similar morphological architecture, with the presence of ventricular outflow tract anomalies but normal great arteries (without transposition) and include tetralogy of Fallot, pulmonary atresia with ventricular septal defect and truncus arteriosus and interrupted aortic arch.3 The most common causes of CTHDs and CHDs are 22q11.2 microdeletion, often detected in DiGeorge syndrome, velocardiofacial syndrome, and conotruncal anomaly face syndrome. Other chromosomal rearrangements are also been reported.1 Congenital disorders of glycosylation (CDGs) are a rapidly growing family of inherited disorders caused by defects in the synthesis of the glycans of glycoproteins or other glycoconjugates4 The most common, CDG-Ia, caused by phosphomannomutase (PMM) deficiency, has been reported in >1000 patients all over the world. In France, >80 families have been diagnosed in the past 10 years. This disorder is clinically heterogeneous and affects the nervous system, either alone (neurological form) or associated with involvement of many other organs, including the heart, liver, gut, and gonads (multisystemic form).5 Typical clinical features …