FASD:The Differential Diagnosis

Dr. Victoria Mok Siu

Medical Genetics Program of Southwestern Ontario

Objectives:

• Recognize factors which may result in some of the symptoms of FASD

• Identify clues that suggest an alternative diagnosis

• Recognize syndromes which may overlap with FASD

Pitfalls in Making the Diagnosis of FASD:

• No single confirmatory test.

• History of exposure may be unavailable or uncertain.

• The brain is sensitive to adverse effects of alcohol at all stages of pregnancy while organ damage primarily occurs in the first 8 weeks of embryonic development.

Pitfalls in Making the Diagnosis of FASD:

• Facial features change with time, may become less evident while learning and behavior problems may become more obvious.

• Must not overlook the possibility of another concurrent diagnosis.

Does this child have FASD?

• Adopted or in foster care

• No information about prenatal exposure

• No information about infancy and early childhood

• Minimal family history

• Behavior and learning problems

Clues that there may be a different or additional diagnosis

• Pregnancy complications

• Specific rather than global delay

• Loss of previously acquired skills

• Unusual odours/food preferences

• Multiple congenital anomalies

• Family history of delayed development

• Social issues

Pregnancy history

• Other exposures (anticonvulsants)

• Flu-like illness (toxoplasmosis, CMV)

• Maternal diabetes/hypertension

• Prematurity

Global vs specific delay

• Delayed speech check hearing

• Delayed fine motor skills check vision

Loss of previously acquired skills

• Neurodegenerative disorders

• Autism/PDD

• Rett syndrome

Unusual odours/food preferences

• Think metabolic

Too many problems look for more than FASD

Importance of family history

I didn’t want to have to mention it, but there’s the matter of genes…

Family history

• Ask about delayed speech, grades repeated, math and reading difficulties

• Who does this child resemble? (anyone with microcephaly, short stature, behavior issues, mental health problems)

• Educational level attained by parents• History of stillbirths, multiple pregnancy

losses (chromosomal abnormality?)• Consanguinity

Social/environmental issues

• Deprivation or neglect?(when was child taken into care?) bonding, empathy

• Was there any abuse – physical/sexual?- head injury? – shaken baby?

• Does the child feel safe now?

• How many changes of home/school/foster family? continuity of learning

The constellation of features is important

• Microcephaly• Epicanthal folds• Short palpebral fissures• Long philtrum

• Stellate iris• Thick lips• Supraventricular aortic

stenosis• “Cocktail party chatter”

• Yes• Yes• Yes• Yes, smooth

• No• Thin lips• Normal heart

• Delayed speech

Williams syndrome FASD

• Short palpebral fissures

• Microcephaly• Congenital heart

defect• Cleft palate• Hypocalcemia• Immunodeficiency

• Yes

• Yes• Usually normal

• Rare• No• No

22q microdeletion

FASD

• Microcephaly• Long philtrum• Thin lips • Depressed nasal

bridge• Anteverted nares

• Synophrys• Short limbs/fingers

• Yes• Yes• Yes• Yes

• Yes

• No• No

de Lange syndrome FASD

Investigations

• Hearing and vision testing

• Other investigations only if suspicious for alternative diagnosis

• It is a capital mistake to theorize before you have all the evidence. It biases the judgment.

• - “A Study in Scarlet”(Sir Arthur Conan Doyle)

Two disorders can co-exist!