CTD is caused by pathogenic variants in SLC6A8, located at Xq28. SLC6A8 contains 13 exons and spreads across 8.5 kb of genomic DNA (gDNA). The presence of hemizygous variants in males and heterozygous variants in females in SLC6A8 provides evidence that CTD is inherited in an X-linked recessive manner. This usually results in hemizygous males having severe symptoms, while heterozygous female carriers tend to have less severe and more varying symptoms.
Creatine transporter defect
N-Acetylglutamate synthase deficiency
Cerebral creatine deficiency
Mitochondrial complex II deficiency
Lysosomal storage disease
D-bifunctional protein deficiency
Mitochondrial trifunctional protein deficiency
Trinucleotide repeat disorder