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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 overlapwith 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 first8 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 moreobvious.

• 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 earlychildhood

• 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, gradesrepeated, 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 pregnancylosses (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 aorticstenosis

• “Cocktail party chatter”

• Yes

• Yes

• Yes

• Yes, smooth

• No

• Thin lips

• Normal heart

• Delayed speech

Williams syndrome FASD



• Short palpebral

fissures

• Microcephaly

• Congenital heartdefect

• Cleft palate

• Hypocalcemia• Immunodeficiency

• Yes

• Yes

• Usually normal

• Rare

• No• No

22q

microdeletionFASD



• 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!

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