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!
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