Holocarboxylase Synthetase Deficiency / Multiple Carboxylase Deficiency

Holocarboxylase Synthetase (HLCS) Deficiency (or Multiple Carboxylase Deficiency) is a rare disorder of biotin metabolism. Most patients with HLCS deficiency present with symptoms in the newborn to early infantile period that include metabolic acidosis and organic aciduria, irritability, lethargy, hypotonia, seizures, coma, developmental delay and dermatitis. Nearly all patients with HLCS deficiency respond to biotin administration, however patients may differ in the level of responsiveness to biotin.

Tests Available

Forms and Documents

Test Details

  • Confirmation of biochemical diagnosis
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancies


4 weeks
2-5 mL Blood - Lavender Top Tube
Buccal Swabs

*Reporting times are typical, but could be extended in situations outside GeneDx's reasonable control.


  • 277.8 Other specified disorders of metabolism
For price inquiries please email zebras@genedx.com

**The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.


  1. Suzuki et al. (2005) Hum Mutat 26:285-290
  2. Santer et al. (2003) Mol Genet Metab 79:160-166
  3. Yang et al (2001) Hum Genet 109:526-534
  4. Dupuis et al. (1996) Hum Mol Genet 5:1011-1016