1. Non-mosaic Down syndrome (10.06) is an example of an impairment that commonly affects
multiple body systems and that we consider significant enough to prevent you from
doing any gainful activity. If you have a different severe impairment(s) that affects
multiple body systems, we must also consider whether your impairment(s) meets the
criteria of a listing in another body system.
2. There are many other impairments that can cause deviation from, or interruption
of, the normal function of the body or interfere with development; for example, congenital
anomalies, chromosomal disorders, dysmorphic syndromes, metabolic disorders, and perinatal
infectious diseases. In these impairments, the degree of deviation or interruption
may vary widely from individual to individual. Therefore, the resulting functional
limitations and the progression of those limitations also vary widely. For this reason,
we evaluate the specific effects of these impairments on you under the listing criteria
in any affected body system(s) on an individual case basis. Examples of such impairments
include triple X syndrome (XXX syndrome), fragile X syndrome, phenylketonuria (PKU),
caudal regression syndrome, and fetal alcohol syndrome.
3. If you have a severe medically determinable impairment(s) that does not meet a
listing, we will consider whether your impairment(s) medically equals a listing. (See
§§ 404.1526 and 416.926.) If your impairment(s) does not meet or medically equal a
listing, you may or may not have the residual functional capacity to engage in substantial
gainful activity. In that situation, we proceed to the fourth and, if necessary, the
fifth step of the sequential evaluation process in §§ 404.1520 and 416.920. We use
the rules in §§404.1594 and 416.994, as appropriate, when we decide whether you continue
to be disabled.
10.01 Category of Impairments, Impairments That Affect Multiple Body Systems
10.06 Non-mosaic Down syndrome, established as described in 10.00B.