FASD: The Differential Diagnosis

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FASDThe Differential Diagnosis

• Dr. Victoria Mok Siu
• Medical Genetics Program of Southwestern Ontario

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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

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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.

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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.

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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

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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

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Pregnancy history

• Other exposures (anticonvulsants)
• Flu-like illness (toxoplasmosis, CMV)
• Maternal diabetes/hypertension
• Prematurity

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Global vs specific delay

• Delayed speech ? check hearing
• Delayed fine motor skills ? check vision

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Loss of previously acquired skills

• Neurodegenerative disorders
• Autism/PDD
• Rett syndrome

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Unusual odours/food preferences

• Think metabolic

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Too many problems ? look for more than FASD
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Importance of family history
I didnt want to have to mention it, but theres
the matter of genes
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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

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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

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The constellation of features is important
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Williams syndrome
FASD

• 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

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22q microdeletion
FASD

• Short palpebral fissures
• Microcephaly
• Congenital heart defect
• Cleft palate
• Hypocalcemia
• Immunodeficiency

• Yes
• Yes
• Usually normal
• Rare
• No
• No

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de Lange syndrome
FASD

• Microcephaly
• Long philtrum
• Thin lips
• Depressed nasal bridge
• Anteverted nares
• Synophrys
• Short limbs/fingers

• Yes
• Yes
• Yes
• Yes
• Yes
• No
• No

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Investigations

• Hearing and vision testing
• Other investigations only if suspicious for
  alternative diagnosis

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• 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)

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Two disorders can co-exist!