inborn disorder of lysosomal amino acid transport free sialic acid storage disease https://www.malacards.org/card/free_sialic_acid_storage_disorders UMLS:C2931872 MEDGEN:419512 MedDRA:10067529 MONDO:0019366 Orphanet:834 MESH:C538523 icd11.foundation:1817428569 NANDO:1200146 free sialic acid storage disease NANDO:2200572 SCTID:278991002 GARD:0010870 MedDRA:10067531 Free sialic acid storage disease (free SASD), is a group of lysosomal storage diseases characterized by a spectrum of clinical manifestations including neurological and developmental disorders with severity ranging from the milder phenotype, Salla disease (SD), to the most severe phenotype, infantile free sialic acid storage disease (ISSD).