CLIPP 29 - T21

Question 1

Common physical findings in Down syndrome (9)

Answer 1

• upslanting palpebral fissures
• small ears
• single palmar crease
• flattened midface
• epicanthal folds
• redundant nuchal skin
• hyptotonia
• gap between first and second toes
• short stature

Question 2

Epidemiology of Down syndrome (who, what, how many)

Answer 2

• higher risk for women >35yo
• 1 in 700 births in US
• Trisomy 21 (most common + most likely), unbalanced translocation (younger women), mosaicism

Question 3

Complications of Down syndrome (6)

Answer 3

• hypothyroidism
• heart defects (50%)
• intestinal stenosis
• umbilical hernia
• atlantoaxial instability (spinal cord impingement)
• predisposition to leukemia

Question 4

Lab tests to confirm diagnosis of Down syndrome

Answer 4

• lymphocyte karyotype (amniocentesis, chorionic villous sampling)
• maternal blood sample
• FISH
• Array comparative genomic hybridization

Question 5

Down syndrome anticipatory guidance

Answer 5

• importance of cervical spine positioning precautions during anesthetic, surgical, or radiographic procedures
• early intervention/IEP
• advocacy

Question 6

Indications for chromosomal analysis (9)

Answer 6

• clinical features of known chromosomal disorder
• unrecognized malformation syndrome
• known genetic condition + more severe findings
• mental retardation + other unusual findings
• stillborn with multiple malformations
• features of chromosome breakage syndrome
• tumor associated with chromosome abnormality
• multiple pregnancy losses
• family history of chromosome rearrangement

Question 7

Fragile X Syndrome

Answer 7

• CGG repeats on FMR1 gene
• long face/large mandible, large ears, large testicles
• second most common genetic cause of intellectual disability

Question 8

Turner Syndrome

Answer 8

• 45, XO
• lymphedema in utero
• webbed neck, low ears, hand/foot edema, hyperconvex nails, “shield” chest with widely spaced nipples
• coarctation of the aorta, short stature, delayed sexual maturation/gonadal dysgenesis
• normal IQ
• 1/2000 live female births

Question 9

Klinefelter Syndrome

Answer 9

• infertility/testicular atrophy, eunichoid body habitus, gynecomastia, low-normal IQ, tall
• increased incidence of behavior problems

Question 10

Trisomy 13 (Patau syndrome)

Answer 10

• 1 in 10000 births
• microphthalmia, microcephaly, polydactyly, cleft lip/palate, cardiac and renal defects, umbilical hernias, cutis aplasia

Question 11

Trisomy 18 (Edwards syndrome)

Answer 11

• 1 in 6000 births
• micrognathia, low-set ears, short neck, overlapping fingers, heart and renal defects, limited hip abduction, rocker-bottom feet

Question 12

Follow-up evaluation in Down Syndrome

Answer 12

• annual thyroid screening, hemoglobin/hematocrit
• vision/hearing screening
• CBC in first month
• Cardiology, early intervention referrals

Question 13

DDX newborn hypotonia (4)

Answer 13

• Down Syndrome
• Benign neonatal hypotonia: no unusual facial or hand features
• Zellweger syndrome: peroxisomal disorder, poorly responsive
• Family resemblance