Severe Combined Immune Deficiency (SCID), IL7R Type

IL7R mutations cause an autosomal recessive form of severe combined immune deficiency (SCID). As in all forms of SCID, cellular and humoral immunity is defective and children present with persistent severe viral, bacterial and fungal infections. In IL7R deficiency, T cells are severely reduced but B and NK cell numbers are normal. IL7R or IL7R alpha are both names for the unique alpha chain of the interleukin 7 receptor, which is necessary for T cell development. In contrast the gamma chain of the IL7 receptor is shared by the receptors for IL2 and IL4, and its deficiency causes a T- B+ NK- form of SCID. ILR7 alpha deficiency is clinically indistinguishable from other forms of T- B+ NK+ SCID caused by mutations in the CD45, CD3D, and CD3E genes and may overlap with other types of SCID. An Omenn-like phenotype has been described.

Tests Available

Forms and Documents

Test Details

IL7R
  • Confirmation of the clinical diagnosis
  • Differential diagnosis from other types of SCID
  • Carrier testing in siblings or other relatives
  • Prenatal diagnosis in at-risk pregnancies
  • Capillary Sequencing

Ordering

302
3 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Dried Blood Spots|Buccal Swabs

Billing

81479x1
No
Yes
  • 279.2 Combined immunity deficiency
* For price inquiries please email zebras@genedx.com

References

  1. Puel, A et al, 1998, Nat Gen 20: 394-397, Defective IL7R expression in T-B+NK+ severe combined immune deficiency
  2. Roifman, C et al, 2000, Blood 96:2803-2807, A partial deficiency of interleukin-7Ralpha is sufficient to abrogate T-cell development and cause severe combined immune deficiency
  3. Giliani S et al, 2006, J Pediatr 148:272-4, Omenn Syndrome in an infant with IL7RA gene mutation
  4. Giliani S et al, 2005, Immunol Rev 203:110-126, Interleukin-7 receptor alpha (IL7-Rappha) deficiency: cellular and molecular bases. Analysis of clinical, immunological, and molecular features in 16 novel mutations
  5. Butte MJ et al, 2007, Clin Immunol 125:159, IL-7 receptor deficient SCID with a unique intronic mutation and post-transplant autoimmunity due to chronic GVHD