• Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit



D13S327; HHH; ORC1; ORNT1

Associated disorders

The SLC25A15 gene is associated with autosomal recessive hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome (MedGen UID: 82815).

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Invitae tests that include this gene:

Pathogenic variants in the SLC25A15 gene are the only known cause of hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome (PMID: 25874378).

The SLC25A15 gene encodes ORNT1 (mitochondrial ornithine transporter 1), the ornithine/citrulline carrier. ORNT1 transports ornithine into and citrulline out of the inner mitochondrial membrane; a process that is important for maintaining the function of the urea cycle and degradation of ornithine (PMID: 25874378).

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
SLC25A15 NM_014252.3