Term
What is Mosaicism?
What is it common in? |
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Definition
Greater or equal to 2 population of cells with different genotypes in same person who has developed from a single fertilized egg
Common for sex chromosomes not autosomes |
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Term
Down Syndrome
What are the two causes of it?
How is the risk of down syndrome increased? |
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Definition
Trisomy 21
Robertsonian translocation t(14;21)
Age
Normal = 1:1000
Age 45 = 1:25 |
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Term
Clinical features of Down syndrome.
Most common (1)?
Craniofacial features (3)?
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Definition
Mental retardaton worsens with age (70 in childhood, 30 in adulthood)
Brushfield spots - white dots in eyes
Epicanthal folds - skin of upper eyelid
Flat facial profile
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Term
| Other clinical features of down syndrome (6) |
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Definition
Simian crease - single transverse fold across palm
Cardiac malformation: 30% of patients (ASD)
GI tract: duodenal stenosis, atresia
Immune system: Unusually susceptible to infections - significant cause of morbidity and mortality
Hematologic: higher risk for leukemia (ALL)
Neurological: strong histological likeness to alzheimer's disease be 35. |
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Term
Patau Syndrome
What is the cause? |
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Definition
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Term
Patau Syndrome
Clinical features (7)
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Definition
Micropthalmia
Microcephaly and mental retardation
cleft lip and palate
renal and cardiac defects
umbilical hernia
rocker bottom feet
polydactyl |
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Term
Edward's Syndrome
What is the cause?
What causes a higher risk of having it? |
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Definition
Trisomy 18
Increased maternal age |
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