Syndromes

Question 1

Williams Syndrome

Answer 1

Cause: Deletion of 26 genes in chromosome 7

Physical features: Elfin-face, low nasal bridge, low-set ears, full lips, small jaw, etc.

Other features: Short stature and slow weight gain; developmental delays; enhanced vocabulary once acquired; charming personality traits

Question 2

Apert Syndrome

Answer 2

Causes: Autosomal dominant disorder caused by changes in the FGFR2 gene

Physical features: High, broad forehead, hypertelorism, retrusion of midface, flat nose with low bridge, CLP in 30% of cases, syndactyly of fingers (and toes?)

Other features: Mild to severe hearing loss, short stature, varying degrees of mental ability

Question 3

Crouzon Syndrome

Answer 3

Causes: Autosomal dominant disorder caused by mutation in the FBFR2 on chromosome 10

Physical features: Craniosyntosis, exopthalamus, midfacial hypoplasia

Other features: Typical cognitive abilities, jaw pain and migraines can occur, conductive hearing loss can occur

Question 4

Anglemann Syndrome

Answer 4

Causes: Duplication of chromosome 15; usually not diagnosed until 3-7 years

Physical features: Prominent mandible, wide mouth, thin upper lip, deep-set eyes

Other features: Developmental delays; seizures, a stiff/jerky gait, happy demeanor and frequent laughter, few or no words with higher receptive skills

Question 5

Cri du Chat syndrome

Answer 5

Causes: An absence of the short arm of the fifth chromosome

Physical features: Low-set ears, narrow oral cavity, microcephaly, micrognathia, and oral clefts

Other features: long, high-pitched cry

Question 6

Down Syndrome

Answer 6

Causes: extra chromosome 21

Physical features: midface dysplasia, shortaned oral and pharyngeal structures, narrow and high palate, macroglossia, short neck, hyperflexible joints

Other features: Low IQ, conductive hearing loss, language delays, voice and artic problems

Question 7

Fragile X Syndrome

Answer 7

Cause: Repetition of Cytosine-guanine-guanine (CGG) on FMR1 gene at the bottom end of the X chromosome

Physical features: Large, long, poorly-formed pinna; macrognathia; enlarged testes; high forehead

Other features: Langauge problems, ID, pragmatics and syntax especially affected

Question 8

Hurler’s Syndrome

Answer 8

Cause: Autosomal recessive deficiency of X-L iduronidase

Physical features: dwarfism, hunchback, ID, short and thick bones, low nasal bridge, midfacial hypoplasia, thick lips, macroglossia, small and malformed teeth

Other features; Sensorineural deafness; most children with Hurler’s die in their early teens

Question 9

Laundau-Kleffner Syndrome

Answer 9

Cause: Unknown

Physical features: NA

Other features: Loss of language between 3 and 7 years of age; may be permanent or temporary with relapses and remissions; 80% develop epilepsy

Question 10

Marfan Syndrome

Answer 10

Cause: Autosomal dominant disorder caused by mutations in the FBN1 gene

Physical features: Loose joints, overgrowth of ribs, long limbs and fingers

Other features: Intelligence unaffected; 70% have restricted lung disease

Question 11

Moebius Syndrome

Answer 11

Cause: Unpredictable occurence

Physical features: Involvement of facial and hypoglossal nerves (and sometimes trigeminal nerve) causing facial paralysis and a perpetually “blank” expression

Other features: Conductive hearing loss, swallowing issues, articulation disorders