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Newborn Screening program

Doctor explaining medications to parents of patient with cystic fibrosis

Disorders Detectable by Newborn Screening

The California Newborn Screening (NBS) Program provides newborn screening to all California babies for all of the core disorders listed on the Recommended Uniform Screening Panel (RUSP)

The RUSP is a list of disorders that are screened at birth and recommended by the Secretary of the Department of Health and Human Services for states to screen as part of their state universal newborn screening programs.

As of October 2020, the following RUSP disorders are screened for in California:

Core conditions are the conditions that newborn screening is specifically designed to identify. ​

The following are disorders that can be detected in the differential diagnosis of a core disorder:

Secondary conditions are the genetic conditions that can be identified when looking for a core condition.  A condition on the newborn screening panel is classified as a “secondary condition” if it is identified unintentionally when screening for one of the core conditions, or as a consequence of confirmatory testing for an out-of-range result of a core condition. ​

Please note: due to biological variability of newborns and differences in detection rates for the various disorders in the newborn period, the California Newborn Screening Program will not identify all newborns with these conditions. While a positive screening result identifies newborns at an increased risk to justify a diagnostic work-up, a negative screening result does not rule out the possibility of a disorder. 

Health care providers should remain watchful for any sign or symptoms of these disorders in their patients. A newborn screening result should not be considered diagnostic, and cannot replace the individualized evaluation and diagnosis of an infant by a well-trained, knowledgeable health care provider.

See below for a list of RUSP disorders, with their definitions and links to helpful resources where available.​​

Definitions and Resources


Severe combined immunodeficiencies (SCID) are caused by a group of disorders that affect the immune system.

The immune system protects the body against infections, viruses, or “foreign" compounds. If the immune system is not working, common illness and infections can be life threatening. SCID can be caused by problems in genes such as IL2RG, ADA, IL-7, and JAK3. These genes usually affect the production of certain types of cells which are critical to immune response.


The most common form of SCID follows an X-linked recessive inheritance. The IL2RG gene is located on the X-chromosome. Males have one X chromosome and one Y chromosome. One non-working copy of IL2RG is enough to cause SCID in males. Females have two X chromosomes, and therefore a second working copy of IL2RG. A female with one working and one non-working IL2RG gene is called a “carrier." It is more common for males to have X-linked recessive SCID than females. A male typically inherits a non-working IL2RG gene from a “carrier" mother.

Other forms of SCID follow autosomal recessive inheritance. This affects males and females equally. In this type of inheritance, people have two copies of a gene that are not working. They typically get one non-working gene from each parent. Parents and other people with one working and one non-working gene are called “carriers." Carriers typically do not have symptoms.

A medical specialist or genetic counselor can help determine which kind of SCID a person has.


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