Lecture 6 - Genetic/Pediatric Disease

Question 1

Monosomy

Answer 1

• form of aneuploidy in cytogenetic disorder

- only one chromosome present in what is supposed to be a pair.

Question 2

Trisomy

Answer 2

• form of aneuploidy in cytogenetic disorder

- three chromosomes present in what is supposed to by only a pair.

Question 3

Mosaicism

Answer 3

• seen in aneuploidy of cytogenetic disorder

- mixture of normal and defected cells in the body

Question 4

Down Syndrome

Answer 4

trisomy 21 – most common autosomal cytogenetic defects.
-Chromosome count: 47.
-older women are at higher risk for having a child with this
-95% of cases, extra 21 chromosome is of maternal origin.
Characterisitics: epicanthic folds, flat facial profile, mental retardation, cardiac malformation, simian crease, wide spacing of 1st/2nd toes, intestinal stenosis

Question 5

Klinefelter’s syndrome

Answer 5

XXY, 47. Sex chromosome defect

• male phenotype with hypogonadism (small testies), testicular atrophy, decreased testosterone, rearely fertile, elongated bodies, reduced facial/body hair, gynecomasti (swelling of breasts in men), mild/undetectable mental deficiencies.
• Appear relatively normal

Question 6

Turner Syndrome

Answer 6

X0, 45. Sec Chromosomal defect

• female phenotype with primary hypogonadism
• majority of fetus w. this defect self abort. Those that do live are affected in: growth retardation, short stature, cystic hygroma (webbed neck), low posterior hairline, kidney/aortic abnormalities. failure of development of secondary sex characteristics, primary amenorrhea, “streak ovaries”, infertility, but usually have normal mental status
• disproved Lyon hypothesis (inactivation of second X chromosome)

Question 7

Polydactyly

Answer 7

• Malformation in Congenital anomalies

- extra digits (toes/finger)

Question 8

Malformation

Answer 8

primary error of morphogenesis due to multifactorial mutation

Question 9

Cyclopes

Answer 9

• malformation in congenital anomalies

- severe form of holoprosencephaly which results in the development of just one eye

Question 10

Holoprosencephaly

Answer 10

• malformation in congenital anomalies

- two lobes of the brain (prosencephalon/forebrain) don’t divide into the usual right vs. left hemisphere

Question 11

Potter Sequence

Answer 11

• a sequence anomaly (multiple anomalies that result secondarily from one localized problem).
• starts with oligo/anhydraminos (little/no amniotic fluid)
• results in: flattened facies, contractures, dislocated hips, and/or pulmonary hypoplasia

Question 12

Hyaline Membrane Disease

Answer 12

• neonatal respiratory distress syndrome that makes it difficult for the newborn to breath due to insufficient surfactant.
• Causes: excessive growth, excessive sedation of mother, fetal head injury, aspiration of blood/amniotic fluid, intrauterine hypoxia (cord accidents)

Question 13

Fetal Hydrops

Answer 13

-accumulation of fluid during uterine growth
Immune cause: antibody induced hemolytic disease of newborn
Non-Immune cause: structural/functional (arrhythmias) cardiac defects; Chromosomal abnormalities (turner’s syndrome, trisomy 21 & 18); Fetal anemia (genetic anemia, twin to twin transfusion syndrome)

Question 14

Hamartoma

Answer 14

-pediatric tumor characterized by overgrowth of tissue that is native to affected organ
(Example of common organ: Lungs develops w. excessive cartilage like tumor)

Question 15

Hemangiomas

Answer 15

Hem = blood; angio = vessel; oma=benign tumor

• overgrowth of blood vessels, most found in the skin
• most common tumors of infancy, benign because it doesn’t spread
• spontaneously regress, gone by age 10

Question 16

Wilms Tumor

Answer 16

• nephroblastoma - malignant tumor
• cancer in kidney
• occurs btwn 2-5 yo
• tumors large size can be felt = symptom patients come in with
• cytology of tumor is good predictor, prognosis very good.