Congenital disorders of glycosylation (CDGs) are heterogeneous group of disorders characterized by defective glycosylation of proteins with multi-systemic clinical manifestations. Underlying problem is defective transfer of monosaccharide residues to proteins due to defective enzymes and transporters in glycosylation pathways. Clinical manifestations range from neurological deficits to cardio-renal problems to immune system defects and clinical presentation widely varies case by case. In general, neurological problems dominate which particularly include fine motor and cognitive deficits. More than 130 congenital disorders of glycosylation have been identified and many more are also being characterized with the advent of cutting-edge genomic tools such as exome and whole genome sequencing. Currently, there are no FDA approved therapies for any congenital disorders of glycosylation.