We have also first time detected and contributed in delineation of some rare metabolic defects like atypical presentation of Arts syndrome (OMIM: #301835),30 autosomal recessive early‐onset peripheral neuropathy caused by MCM3AP gene variants (OMIM: #603294),31FLAD1‐associated multiple acyl‐CoA dehydrogenase deficiency (OMIM: #255100),32 SLC35A2‐CDG defect (OMIM: #314375),33 diverse phenotypes of NDUFB11 gene defect (OMIM: #301021),34 and early onset mitochondrial disease caused by dominant variants in SLC25A4 (OMIM: #103220).35 This evidence concerns the gene SLC35A2 and Lethal ataxia with deafness and optic atrophy.