Pediatric Disease Flashcards
1
Q
What are congenital abnormalities?
A
- defects seen at birth
- range from mild to fatal
- mostly affect cardio. system
- associated with genetic abnormalities, environmental, maternal factors
2
Q
What are the 2 common pediatric/prenatal diseases?
A
congenital abnormalities and prematurity
3
Q
What are mutations?
A
- from alteration in DNA sequence
- point mutations cause common genetic diseases
4
Q
What are the 5 types of mutations?
A
- silent (no effect)
- missense (code for different protein)
- nonsense (stop signal reading code)
- frameshift (alters reading frame)
- point ( substituting, adding, deleting a single nucleotide)
5
Q
What are multifactorial disorders?
A
result from changes in many genes by chromosomal deletions, duplications, inversions, insertions, and translocations
6
Q
What are epigenetic changes?
A
- modulate expression without altering DNA sequence
- post-translational modification and gene silencing by microRNAs
7
Q
What are Mendelian Disorders?
A
- alterations in singles genes
- inherited through germline
- extent of disease depends on penetrance
- characterized by clustering of one unusual disease ina family
8
Q
What can a family pedigree indicate a pattern of inheritance as?
A
- autosomal dominant
- autosomal recessive
- sex-linked dominant
- sex-linked recessive
9
Q
What are autosomal dominant disorders?
A
- caused by point mutations in one allele
- produce abnormal receptor/structural protein
- equal susceptibility between male & female
- 50% risk among siblings
- expressed in heterozygous state
10
Q
What is Marfan syndrome?
A
- autosomal dominant
- point mutations in glycoprotein fibrillin 1 gene (FBN1)
- deficient deposition of elastin fibers
- pts are tall with scaphoid chest, arachnodactyly (long digits), double jointed, subluxation (ocular dislocation)
- bone overgrowth related to TGF-beta
- risk for aortic dissection
11
Q
What is familial hypercholesterolemia?
A
- autosomal dominant
- from mutations in low density lipoprotein (LDL) receptor gene
- heterozygotes 2-3 times increased plasma cholesterol (more common)
- homoxygotes > 5 times increased plasma cholesterol
12
Q
What is anemia?
A
- diminished O2 capacity
- caused by inadequate RBC production
- inherited/acquired/infectious
13
Q
What are the important numbers in anemia?
A
- RBC= 4.2-5.6 males; 3.8-5 females
- hematocrit= 38-48% males; 35-44% females
- MCV= 81-100 fl
- RDW= <15%
- Hgb= 13 males; 12 females
14
Q
What is Hereditary spherocytosis?
A
- autosomal dominant
- results from mutations in ankyrins
- have aplastic crises (shut down of erythropoeisis)
- anisocytosis: unequal RBC size
- Howell-Jolly body: basophilic nuclear DNA remnants in circulating erythrocytes
15
Q
What are autosomal recessive disorders?
A
- mutation by BOTH alleles
- homozygotic proband vs heterozygotic carrier
- largest group of Mendelian disirders
- 25% risk among siblings
- inherited equally in males & females
- can skip generations
- enzymatic effects in metabolism/storage
16
Q
What is lysosomal storage disease (Tay-Sachs disease)?
A
- autosomal recessive
- accumulation of gangliosides due ot alpha-subunit of hexosaminidase A
- catastrophic infantile (usually kills infants)
17
Q
What is Hurler’s disease?
A
- autosomal recessive
- MPS type 1: deficiency of alpha-L-iduronidase
- skin & musculoskeletal system affected
- growth retardation/coarse facial & skeletal features
18
Q
What is Hunter’s disease?
A
- X-linked recessive
- MPS type 2: deficiency of L-iduronate sulfatase
- results in similar cellular accumulation of heparan sulfate and dematam sulfate as Hurler’s
19
Q
What is sickle cell anemia?
A
- autosomal recessive
- affects 15.5:1000
- hemoglobin S: composed of 2 mutant beta-globin chains & 2 normal alpha-globin chains
- crescent/sickle shaped RBC
- ischemic microinfarcts and pain crisis
- chronic damage -> hemolytic anemia
- treatments: blood transfusions
- hydroxyurea
20
Q
What is cycstic fibrosis?
A
- autosomal recessive
- mutations in CFTR
- loss of Cl- channel promotes excessive tissue Na+ absorption & water retention
- results in decreased surface water content in secreted mucin
21
Q
What is the clinical course of cycstic fibrosis?
A
- meconium ileus: fecal congestion in the ileum
- pancreatic insuff, with recurrent pancreatitis
- mucus plugging contributes to cardiopulmonary complications
- predisposition to bacterial infection
- respiratory failure is most common cause of death
22
Q
What is phenylketonuria?
A
- autosomal recessive
- lack of phenylalanine hydroxylase
- results in hyperphenylalanine, phenylketonuria, and phenylalanine secreted in sweat
- present in 6 months with severe mental retardation, failure to walk/talk, seizures
- controlled by dietary restriction of phenylalanine
23
Q
What are X-chromosome linked disorders?
A
- transmitted by homozygous or heterozygous female carriers
- males (XY) can ONLY pass it on to their daughters
- can be recessive or dominant
- no known Y-chromosomal diseases
24
Q
What are X-linked recessive diseases?
A
- abnormalities on X chromosome
- females are carriers who pass disease to sons
