Chromosome Disorders Flashcards
What chromosomal disorder has a recurrence risk of 1/800?
Trisomy 21-47, XY or XX, +21 “Down syndrome”
What chromosome disorder is caused by aneuploidy, nondisjunction at c21, usually at maternal meiosis 1
Trisomy 21-47, XY or XX, +21 “Down syndrome”
The following phenotype is characteristic of what chromosomal disorder:
- congenital hypotonia, facial dysmorphology, moderate mental retardation, communication disorder, 40% congenital heart disease hearing loss due to otitis, media strabismus and refractive errors, hypothyroidism, upturned palpebral fissures,1st and 2nd toe gap
Trisomy 21-47, XY or XX, +21 “Down syndrome”
In what chromosomal disorder are 95% of trisomies due to maternal nondisjunction, 95% non familial?
Trisomy 21-47, XY or XX, +21 “Down syndrome”
What chromosomal disorder is caused by aneuploidy, fusion of acrocentric chromosomes near the centromere w/ loss of short arms, 14p and 21 (parent = 45c)
Robertsonian Translocation - 46, XY or XX, t (14,21)
The following phenotype is characteristic of what chromosomal disorder:
- hypotonia, facial dysmorphology, moderate mental retardation, communication disorder, 40% congenital heart disease, hearing loss due to otitis media, strabismus and refractive errors, hypothyroidism, 1st and 2nd toe gap
Robertsonian Translocation - 46, XY or XX, t (14,21)
What chromosomal disorder is 4% of trisomies and karyotype of parents?
Robertsonian Translocation - 46, XY or XX, t (14,21)
What chromosomal disorder has a mixture of normal cells and trisomic cells?
Mosaic trisomy
What chromosomal disorder represents 1% of trisomies?
Mosaic Trisomy
What chromosomal disorder has aneuploidy nondisjunction of c18?
Trisomy 18 “Edwards syndrome”
What chromosomal disorder has a 1/5000 to 1/7500 recurrence risk?
Trisomy 18 “Edwards syndrome”
What chromosomal disorder has the following phenotype:
- short sternum, overlapping fingers w/ clenched fist, genital anomaly and left foot with missing digits, cardiac defect, renal anomaly, severe mental retardation, facial features: low frontal hairline, short palpebral fissures, blunt nasal tip w/ small nostrils, small chin, high nasal bridge, fawn like ears?
Trisomy 18 “Edwards syndrome”
What chromosomal disorders are semi lethal?
Trisomy 18 “Edwards syndrome”
Trisomy 13 “patau’s syndrome”
What chromosomal disorder has aneuploidy nondisjunction of c13?
Trisomy 13 “patau’s syndrome”
What chromosomal disorder has a recurrence risk of 1/10,000 to 1/20,000?
Trisomy 13 “patau’s syndrome”
What chromosomal disorder has the following phenotype:
- holoprosencephaly w/ premaxillary agenesis (cleft lip/palate), microphthalmia, fixed fingers, polydactyly, cryptochidism, abnormal scrotum, cardiac defect, cystic kidneys, short prominent sternum, omphalocele, micropenis, rocker bottom feet
Trisomy 13 “patau’s syndrome”
In what chromosomal disorder is it necessary to karyotype the parents?
Trisomy 13 “patau’s syndrome”
What chromosomal disorder has a 100% transmittance from carrier to offspring?
Trisomy 21-46, XX or XY, t(21,21)
What chromosomal disorder has nondisjunction of c8 in some cells only?
Trisomy 8 mosaic -46
What chromosomal disorder has the following phenotype:
- facial dysmorphology, strabismus (esotropia), moderate mental retardation?
Trisomy 8 mosaic -46
In what chromosomal disorder is the full trisomy 8 lethal?
Trisomy 8 mosaic -46
In what chromosomal disorder is he zygote dispermy or polar body retained?
Triploidy - XXX
The following phenotype is characteristic of what chromosomal disorder:
- severe growth restriction, syndactyly, dysmorphic fetus
Triploidy - XXX
What chromosomal disorder is 100% fatal?
Triploidy - XXX
In what chromosomal disorder does the affected individual receive 3 copies of every chromosome?
Triploidy - XXX
What are examples of chromosomal disorders?
Trisomy 21-47, XY or XX, +21 (Down's Syndrome) Robertsonian Translocation-46, XY or XX, t(14,21) Mosaic Trisomy Trisomy 18 "Edward's Syndrome" Trisomy 13 "Patau's Syndrome" Trisomy 21-46, XX or XY, t(21,21) Trisomy 8 mosaic -46 Triploidy- XXX
