Natural History Study of SCID Disorders

Inclusion Criteria:

Stratum A: Typical SCID (formerly referred to as Classic SCID)- -Subjects who meet the following inclusion criteria and the intention is to treat with allogeneic hematopoietic cell transplant (HCT) are eligible for enrollment into Stratum A (Typical SCID) of the study:

Absence or very low number of T cells (CD3 T cells <300/microliter) AND
No or very low T cell function (<10% of lower limit of normal) as measured by response to phytohemagglutinin (PHA) OR
T cells of maternal origin present.

Stratum B: Leaky SCID, Omenn Syndrome, Reticular Dysgenesis-

-Subjects who meet the following criteria and the intention is to treat with HCT are eligible for enrollment into Stratum B:

Leaky SCID:

Maternal lymphocytes tested for and not detected AND

Either one or both of the following (a,b) :

a.) <50% of lower limit of normal T cell function as measured by response to PHA, OR response to anti-CD3/CD28 antibody
b.) Absent or <30% of lower limit of normal proliferative responses to candida and tetanus toxoid antigens

AND at least two of the following (a through e):

a.) Reduced number of CD3 T cells

age ≤2 years: <1500/microliter
age >2 years and ≤4 years: <800/microliter
age >4 years: <600/microliter

b.) ≥80% of CD3+ or CD4+ T cells that are CD45RO+

AND/OR >80% of CD3+ or CD4+ T cells are CD62L negative
AND/OR >50% of CD3+ or CD4+T cells express HLA-DR (at <4 years of age)
AND/OR are oligoclonal T cells
c.) Hypomorphic mutation in IL2RG in a male, or homozygous hypomorphic mutation or compound heterozygosity with ≥1 hypomorphic mutation in an autosomal SCID-causing gene
d.) Low T Cell Receptor Excision Circles (TRECs) and/or the percentage of CD4+/45RA+/CD31+ or CD4+/45RA+/CD62L+ cells is below the lower limit of normal.
e.) Functional testing in vitro supporting impaired, but not absent, activity of the mutant protein, AND
Does not meet criteria for Omenn Syndrome.

Omenn Syndrome:

Generalized skin rash

Maternal lymphocytes tested for and not detected;

--Note: If maternal engraftment was not assessed and ruled out, the subject is not eligible as Omenn Syndrome.

≥80% of CD3+ or CD4+ T cells are CD45RO+ AND/OR

80% of CD3+ or CD4+T cells are CD62L negative AND/OR
50% of CD3+ or CD4+ T cells express HLA-DR (at <2 years of age);
Absent or low (< 30% lower limit of normal) T cell proliferation response to antigens (Candida, tetanus) to which the subject has been exposed

NOTE: If proliferation to antigen was not performed, but at least 4 of the following 9 supportive criteria, at least one of which must be among those marked with an asterisk (*) below are present, the subject is eligible as Omenn Syndrome:

Hepatomegaly
Splenomegaly
Lymphadenopathy
Elevated IgE
Elevated absolute eosinophil count
*Oligoclonal T cells measured by CDR3 length or flow cytometry
*Proliferation to PHA is reduced <50% of lower limit of normal or SI <30
*Hypomorphic mutation in a SCID causing gene
Low TRECS and/or the percentage of CD4+/45RA+/CD31+ or CD4+/45RA+/CD62L+ cells is below the lower limit of normal.

Reticular Dysgenesis:

Absence or very low number of T cells (CD3 <300/µL
No or very low (<10% lower limit of normal) T cell response to PHA
Severe neutropenia (absolute neutrophil count < 200 /µL) AND

≥2 of the following (a,b,c):

a.) Sensori-neural deafness
b.) Deficiency of marrow granulopoiesis on bone marrow examination
c.) A pathogenic mutation in the adenylate kinase 2 (AK2) gene identified.

Stratum C:

Subjects who meet the following criteria and the intention is to treat with therapy other than allogeneic HCT, primarily PEG-ADA ERT or gene therapy with autologous modified (gene transduced) cells, are eligible for enrollment into

Stratum C:

ADA Deficient SCID with intention to treat with PEG-ADA ERT
ADA Deficient SCID with intention to treat with gene therapy
X-linked SCID with intention to treat with gene therapy
Any SCID patient previously treated with a thymus transplant (includes intention to treat with HCT, as well as PEG-ADA ERT or gene therapy)
Any SCID patient who received therapy for SCID deemed "non-standard" or "investigational", including in utero procedures.

Exclusion Criteria:

-Subjects who meet any of the following exclusion criteria are disqualified from enrollment in Strata A, B, or C of the study:

Presence of an Human Immunodeficiency Virus (HIV) infection (by PCR) or other cause of secondary immunodeficiency
Presence of DiGeorge syndrome
MHC Class I and MHC Class II antigen deficiency, and
Metabolic conditions that imitate SCID or related disorders such as folate transporter deficiency, severe zinc deficiency or transcobalamin deficiency.

For more information on this trial, visit clinicaltrials.gov.