Chapter 6 Q&A Flashcards
(42 cards)
- 4 yo girl presents for PE; small head circumference, thin upper lip, low-bridge nose; mild mental retardation; parents state she is often emotional; what defects account for findings?
Alcohol abuse (fetal alcohol syndrome with growth retardation, CNS dysfunction, facial dysmorphology)
- 12 mo boy goes to ER and there is recent fracture of right ulna and healing fractures; blue sclerae; patient has mutation with which proteins?
Collagen (osteogenesis imperfecta, or brittle bone disease; the fragility of bone due to type I collagen synthesis affected)
- 28 yo woman has stillborn with neural tube defect; defect caused by error of morphogenesis that occurred at which stage of development?
20-40 days (dysfunction of the neural tube to close around day 23-26 of gestation)
- 20 yo man has numerous pigmented patches and pedunculated skin tumors on chest; benign neoplasm from Schwann cells; parents don’t have signs; what is the mutation for?
GTPase activating protein: neurofibromatosis type 1 characterized by disfiguring neurofibromas, areas of dark pigmentation of skin, pigmented lesions of the iris; the GTPases inactivate ras protein
- Patient with pigmented patches is at increased risk of developing which neoplasm?
Neurofibrosarcoma (a complication of neurofibromatosis type 1)
- 25 yo pregnant woman, 16 weeks gestation; US shows 3 cm neural tube defect in thoracic spine; what would screening test measure for in the serum?
Alpha-fetoprotein (AFP): will enable detection of all anencephalic features
- 25 yo man presents as tall, long fingers; later has dissecting aortic aneurysm; what mutation is here?
Fibrillin: missense mutation in gene for fibrillin leads to Marfan’s
- What is pattern of inheritance with Marfan’s?
Autosomal dominant
- 12 mo boy shows progressive weakness, mental deterioration, loss of vision; labs show decreased hexosaminidase A; child becomes blind and dies at 3 years of age; what is the path?
Accumulation of unmetabolized substrate
- Parents of kid with hexosaminidase A deficiency have four sons, two daughters, how many of their children expected to be asymptomatic?
3 (Tay-Sachs is autosomal recessive, so half expected to be asymptomatic)
- 4 yo boy has pneumonia and respiratory distress; bowel movements are greasy and have pungent odor; sweat-chloride test positive; why the steatorrhea?
Lack of pancreatic enzyme secretion (CF characterized by chronic pulmonary disease, deficient exocrine pancreatic function, and other complications of inspissated mucus in number of organs)
- For 4 yo boy with pneumonia and respiratory distress, what mutations are expected?
Membrane ion channel (Cl)
- 10 yo child presents with xanthomas on extensor surfaces of forearms; labs show cholesterol of 820 mg/dL; child’s mother and maternal grandfather with elevated serum cholesterol; where is the mutation?
LDL receptor
- 10 mo boy is fair skinned, blond hair; has mousy odor; inborn error of aa metabolism; to prevent mental retardation, what aa’s should be lacking?
Phenylalanine (PKU with autosomal recessive disease and mental deterioration)
- What is the path for the 10 mo fair skinned kid?
Accumulation of unmetabolized substrate
- 4 yo boy with pliable skin; bruises easily; joints hyperextended; deficiency of lysyl hydroxylase; what is the abnormal cell/tissue component?
Collagen fibers: Ehler Danlos (autosomal dominant, type IV)
- 25 yo woman with recurrent bone pain, increasing abdo girth; massive hepatosplenomegaly; radiolucent bone defects; large cells with fibrillar appearance reminscent of wrinkled tissue paper; where is the mutation?
Glucosidase (Gaucher disease, with Gaucher cells that have lipid-laden macrophages seen in red pulp of spleen, liver sinusoids, lymph nodes, lungs, and bone marrow)
- How do you get hepatosplenomegaly, bone pain in 25 yo woman?
Accumulation of unmetabolized substrate
- Neonate with severe motor dysfunction of lower extermities; vertebral bodies in lumbar region lack posterior arches; space under membrane has tissue with meninges and spinal cord; what can reduce incidence of neural tube defects?
Folic acid
- Parents of infant with cleft lip and palate; what can cause this error of morphogenesis?
Structural chromosomal abnormality (multifactorial inheritance, teratogens also causes of the cleft lip and palate)
- 4 yo boy has weakness in pelvic and shoulder girdles and calf muscle enlarged; CK levels elevated; foci of muscle fiber necrosis, myophagocytosis, regenerating fibers, fibrosis; where would there be alterations of the primary transcript?
Dystrophin (DMD, a severe X0linked condition with degeneration of the muscles)
- What can cause patient death from DMD?
Cardiomyopathy
- 22 yo man complains about inability to conceive child; patient is tall, gynecomastia and testicular atrophy; incrased levels of FSH; chromosomal abnormality?
Meiotic nondisjunction (Klinefelter syndrom, or testicular dysgenesis, usually involving one extra X chromosome, ie XXY)
- 35 yo pregnant woman has baby prematurely at 28 weeks gestation; neonate becomes SOB, with intercostal retraction and nasal flaring during respiration; dies of respiratory insufficiency and intraventricular hemorrhage; what is the eosinophilic material?
Fibrin (respiratory distress syndrom and deficiency of surfactant; collapse of alveoli)