Genetics

Question 1

Hx for dysmorphic child

Answer 1

• fam hx - birth defects, sudden death, infertility, genetics
• consanguinity
• ethnicity
• antenatal: IVF, exposures, screening, complications
• delivery: APGARS, etc
• post natal: growth, LDs, health, vision, behaviour

Question 2

areas for examine for dysmorphia

Answer 2

skull, eyes, ears, teeth, nose bridge, nares, lips, jaw, neck

chest, spine, sacrum, nipples, hernias, clinodactly, palmar creases, heels, skin

Question 3

Possible testing modalilities

Answer 3

FISH (specific duplication / deletion)
karyotype
microarray
single gene/ panels
whole exome sequencing 
enzyme testing for metabolic disorders

Question 4

Down Syndrome Physical Features

Answer 4

• hypotonia, short stature
• flattened faces, nuchal skin, short neck, large fontaelles, small nose, low bridge, large tongue
• up-slanting eyes, inner epicanthal folds, brushfield spots, myopia, nystagmus, strabismus
• low set ears, otitis media
• transverse palmar crease, clinodactlyly, absent middle phalanx of 5th digit
• hyopspadius, undescended testes

Question 5

Down syndrome associated features / conditions

Answer 5

• AVSD, VSD
• dysphagia, GERD, esophageal atresia, hirschprungs, celiac, OSA
• male infertility
• seizures, alzheimers
• resp infections
• motor, language, cognitive delay, behavioural
• atlanto-axial instability

Question 6

Testing for Down’s Syndrome

Answer 6

• antenatal amniocentesis or NIPT
• FISH for chromosom 21 (quick but doesn’t show balanced translocations / recurrence risk)
• karyotype and g banding

Question 7

surveillance for Down’s

Answer 7

• echo (VSD) 1x
• swallowing assessment if hypotonia
• opthalmology
• hearing annually
• cbc: myeloprolif disorder, polycythemia
• Hb annually (+/ferritin)
• TSH annually
• spine films if myopathy symptoms
• 23 valent pneumococcal vaccine if cardiopulmonary disease (ages 2+)

Question 8

trisomy 13

Answer 8

Patau syndrome

• micropthalmia
• polydactyly
• celf palate
• cardiac
• forebrain anomaly
• genitourinary
• rocker bottom feet
• scalp anomalies

Question 9

edwards syndrome

Answer 9

trisomy 18

• cardiac
• renal
• craciofacial anomalies
• clenched fist + overlapping fingers
• rocker bottom feet

Question 10

fragile x syndrome etiology

Answer 10

unstable CGG expansion in FMR1 gene, x chromosome

Question 11

presentation of fragile x syndrome

Answer 11

• ID, language + motor delay
• autism, ADD, anxiety, lability
• long narrow face, prominent jaw + forehead, protuberant ears, arched palate, strabismus, chronic OM
• joint laxity, soft skin, scoliosis, flat + club feet
• mitral valve prolapse
• macro-orchidism
• GERD
• fast growth in childhood, slow in adolescence, short final
• hypotonia, seizures, tremor/ataxia
• POI in women

Question 12

DiGeorge Syndrome

Answer 12

22q11. 1 deletion
- spont or inhereted
- impaired pharyngeal pouch development
- triad: conotruncal cardiac anomaly, immunodeficiency (thymus), hypocalcemia (parathyroid)
- other: low set ears, clef palat, renal anomaly, esophageal dysmotility, feeding issues, CNS, anomalies, spinal anomalies, hearing impairment, dev delay, behaviour

Question 13

Prader Willi Syndrome

Answer 13

Hypotonia
Childhood onset obesity
Bitemporal constriction
Tapered fingers
Undescended testes
Feeding inability – infants
Constant hunger – child/adult
Potential for sudden death
Childhood/adolescent psych disorders
Short stature, delayed puberty

Question 14

beckwith-weidemann

Answer 14

Macrosomia
Macroglossia
Omphalocele 
Hemihyperplasia
Neonatal hypoglycemia
Ear creases / pits
Wilm’s tumor
Visceromegaly

Question 15

Noonan Syndrome

Answer 15

Micrognathia
Large forehead
Wide spaced, down slanting eyes
Epicanthal folds
Short, broad nose, deep philtrum
Oval, low ears
Nuchal skin folds
Swollen hands + feet
Neck webbing
Pectus defromity
Wide spaced nipples
Triangle shaped head
Cardiac: valular disease, HOCM, ASD
GI motility issues
Bleeding disorders
\+/-mild ID, learning difficulties, speech disorders