(Page 3 of 5)

Individual dysmorphic features are not unique to any particular syndrome. Even rare defects or certain clusters of dysmorphic features can appear in multiple syndromes. Therefore, a process of differential diagnosis is essential in making an accurate FAS diagnosis. Features that discriminate these disorders from FAS have been described. Certain syndromes have single overlapping features with FAS. With the exception of toluene embryopathy, no other known syndrome has the full constellation of small palpebral fissures, thin vermillion border, and smooth philtrum. However, for certain syndromes (e.g., Williams syndrome, Dubowitz syndrome, or fetal dilantin syndrome), the overall constellation of features (primary, occasional features, or both) is similar to FAS, and these syndromes should be considered in particular when completing the differential diagnosis.

Growth retardation and deficiencies occur among children, adolescents, and adults for multiple reasons. Insufficient nutrition could be a particular problem for infants with poor sucking responses who fail to thrive. In addition, certain genetic disorders result in specific growth deficiencies (e.g., dwarfism). Prenatal growth retardation can result from multiple factors, including maternal smoking or other behaviors leading to hypoxia, poor maternal nutrition, or genetic disorders unrelated to maternal alcohol consumption. Both environmental and genetic bases for growth retardation should be considered for differential diagnosis when considering a FAS diagnosis. Finally, because a threshold of < 10th percentile (rather than the lower threshold of the third percentile commonly used to denote growth retardation) was adopted, certain children will be classified as being consistent with this criterion for reasons other than prenatal exposure to alcohol (e.g., parents having short stature). However, because the diagnosis of FAS is made only when facial dysmorphia and CNS abnormalities also are present, the increased sensitivity achieved with the 10th percentile was selected.

Differential diagnosis of CNS abnormities involves not only ruling out other disorders but also specifying simultaneously occurring disorders. CNS deficits associated with FAS (especially functional deficits) can be produced by multiple factors in addition to prenatal alcohol exposure. Observed functional deficits should be determined not to be better explained by other causes. In addition to other organic syndromes that produce deficits in one or more of the previously cited domains (e.g., Williams syndrome and Down syndrome), disrupted home environments or other external factors can produce functional deficits in multiple domains that overlap those affected by FAS. In making a differential diagnosis of FAS, the clinician should evaluate CNS abnormalities in conjunction with dysmorphia and laboratory findings. CNS abnormalities resulting from environmental influences (e.g., abuse or neglect, disruptive homes, and lack of opportunities) are harder to differentiate. To assist with differential diagnosis between FAS and environmental causes for CNS abnormalities, clinicians should obtain a complete, detailed history for the person and family members.

In addition to ruling out other causes for CNS abnormalities, a complete diagnosis should identify and specify other disorders that can coexist with FAS (e.g., autism, conduct disorder, or oppositional defiant disorder). A particular person might have a conduct disorder in addition to FAS; however, not all persons with FAS have conduct disorders, and not all persons with conduct disorders have FAS. Certain functional deficits might lead to additional behavior problems. For example, a child with an attention problem also could have conduct disorder. Clinicians should consider organic causes, environmental contributions, and comorbidity for both inclusive and exclusive purposes when evaluating a person for a FAS diagnosis. Because differential diagnosis for CNS abnormalities within a FAS diagnosis is difficult, the evaluation should be conducted by professionals trained in both the features of FAS and those of a broad array of birth defects and developmental disabilities.

Conditions Consistent with a Subset
of Diagnostic Criteria for FAS

The majority of persons with deficits resulting from prenatal exposure to alcohol do not express all the features necessary for a FAS diagnosis. Sufficient scientific evidence is not available to define diagnostic criteria for any prenatal alcohol-related condition other than FAS. Persons who have the neurodevelopment deficits required for a FAS diagnosis but who do not have all three facial features or growth deficits might not receive a diagnosis and so not be provided with services. Ongoing funding has been provided by the National Institute on Alcohol Abuse and Alcoholism to conduct research that might lead to evidence-based diagnostic criteria for persons with other conditions caused by prenatal alcohol use. CDC is using a collaborative database of neurodevelopment data from five intervention studies to explore the nature of persons who could be considered in the diagnostic category of alcohol related neurodevelopment disorder, as well as data from a prospective cohort study in Denmark of children aged 5 years. FAS is the only diagnostic category with scientific evidence to support clinical criteria at this time. As future data become available, these guidelines can be refined and expanded to delineate other conditions resulting from prenatal alcohol exposure.

Mental Health Problems and Other Lifelong Consequences

FAS has lifelong consequences. Common FAS-related mental health conditions (excluding attention problems) reported include conduct disorders, oppositional defiant disorders, anxiety disorders, adjustment disorders, sleep disorders, and depression. Although attention problems can be classified as a mental health issue or psychiatric condition, in these guidelines, they are treated as a primary deficit resulting from alcohol-related CNS damage rather than a secondary mental health concern. Decreased adaptive skills and increased problems with daily living abilities have been documented (e.g., dependent living conditions, disrupted school experiences, poor employment records, and encounters with law enforcement, including incarceration) among persons with FAS. These mental health-related consequences should not be used for diagnosis. However, they are prevalent among persons with FAS and are likely to result in referral and comprehensive diagnostic evaluation.

Tags: Alcoholism

About the Author

www.cdc.gov
The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.