Genetics Flashcards
Karyotype of Down syndrome
Trisomy 21
T/F
Blank facial expression is common in Down syndrome
False
Typical features in Down syndrome
Microcephaly
Low, flat nasal bridge
Oblique upward- slanting eyes
Low set ears
Short nose
Open mouth
Large protruding tongue
Single palmar crease
Saddle gap
Hypotonia
Hepatosplenomegaly
Down syndrome is associated with (complications)
Leukemia- Hepatosplenomegaly
Anal abnormalities
Duodenal atresia
Hirschsprung disease
Developmental delay
Hypothyroidism
The growth chart used in down syndrome
Down syndrome specific growth chart
Ways how trisomy 21 occurs in down syndrome
Non- disjunction (95% of the cases)
Translocation 4%
Mosaicism 1%
Risk of recurrence of Down syndrome is highest in
Translocation ( 21:21 translocation is 100%)
Low- set ears
At least 1/3 of the ear doesn’t protrude out from an imaginary line drawn from the outer corner of the eye and the eye
confirmatory test in Genetic disorders
Karyotyping
Referrals that should be done for Down syndrome
Cardiology
Steps of Mx if there’s a developmental delay in down syndrome
Refer to rehabilitation programs
Physiotherapy
Speech therapy
Hearing assessment
Visual assessment
Mx of down syndrome
1.Karyotyping - confirm the Dx
2.Ix for possible complications( Echo, USS Abd, CBC, Blood picture, Thyroid function test)
3.Growth and development assessment
4.Thyroid supplementation ( if hypo)
5.Refer to a cardiologist ( if cardiac issues)
6.Refer to a special school
7.If there’s a growth delay - refer to rehabilitation programs
8. Genetic counselling to parents
2nd Most common trisomy
Edward syndrome
Edward syndrome is most seen in males/females?
females (80%)
T/F
Majority of edward syndrome will be stillbirths
True
Reason for low survival rate in Edward syndrome
Heart abnormalities
Kidney malformations
Sx of Edwards Syndrome
Small head
malformed ears
Widely- spaced eyes
Clenched hands
low set ears
overlapping fingers
Widely- spaced eyes?
gap between the two eyes is more than the gap for one eye
Sx of patau Syndrome
Small head
Cleft lip/ palate
Absent eyebrows
Dysplastic/ malformed ears
Clenched hands
Polydactyly
Undescended or abnormal testes
Karyotype of Patau syndrome
Trisomy 13
Turner syndrome karyotype
45 chromosomes. XO
Most cases of turner syndrome is diagnosed late. When?
When performing tests for being unable to get PG
Hormone deficiencies in Turner syndrome
Reduced GH
Reduced estrogen
Reduced Thyroxine
Sx of turners
Short stature
Low posterior neckline
Webbing of neck
Shield chest
Edema of dorsum of hands and feets
Cubitus varus
Rudimentary ovaries, uterus
Cardiac abnormalities
shield chest is seen in
Turner syndrome - widely spaced nipples
low set ears are seen in
Down syndrome
Edward syndrome
How is the cognition in turner syndrome
Mostly normal
Mx of turner syndrome
Educate the parents- genetic counselling
Refer to a cardiologist
Hormone replacement therapy
Family planing advices
Common cardiac complication associated with turner
CoA
Cubitus varus seen in
Turner syndrome
Saddle gap is seen in
Down syndrome
3 GIT conditions associated with Down syndrome
Duodenal atresia
Hirschsprung disease
Klinefelters syndrome karyotype
44 XXY
Klinefelter syndrome presents as male/female
both males and females