Case#: Index patient, 6 years old (age at report), caucasian, male

DiseaseAssertion: Creatine transporter deficiency

FamilyInfo: Mother and maternal grandmother have history of learning disabilities, severely retarded uncle, unnaffected aunt

CasePresentingHPOs: HP:0001290 , HP:0006863, HP:0000750, HP:0001256 (Hypotonia, severe expressive language delay, severe speech delay, mild mental retardation)

CaseHPOFreeText: N/A

CaseNotHPOs: N/A

CaseNotHPOFreeText: N/A

Biochemical analyte testing: Increased creatine levels in urine and plasma

Brain Magnetic Resonance Spectroscopy (MRS): Brain proton MRS revealed an almost complete absence of the creatine signal.

Creatine uptake assay: Creatine uptake was measured in total cell lysates, creatine concentration of 25 μM uptake level was negligible, and creatine concentration of1 25 μM uptake level was negligible.

Variant: No varient ID directly identified. Hemizygous nonsense mutation, A 1539C→T transition in SLC6A8 (GenBank accession number NM_005629) resulted in the substitution of an arginine codon by a termination codon (R514→X).

ClinVarID: N/A

CAID: N/A

gnomAD: N/A

Zygosity: Hemizygous

MaternalGenotype: grandmother aunt, and mother heterozygous for mutation

AdditionalParentalTesting: N/A

AlsoPublished: PMID: 11261517