VII - Genetic and Pediatric Diseases Flashcards
These disorders are derived from one’s parents, transmitted through gametes through the generations, and are therefore familial.
Hereditary disorders(TOPNOTCH)
This term literally means “present at birth”.
Congenital(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
This term refers to permanent changes in the DNA.
Mutations(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
This type of mutation results from the substitution of a single nucleotide base by a different base, resulting in the replacement of one amino acid by another.
Missense mutation(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
This type of mutation results in the replacement of one amino acid by a stop codon, resulting in chain termination.
Nonsense mutation(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
Missense, nonsense and silent mutations are examples of ________ mutations, wherein only one base pair is replaced.
Point mutations(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
This type of mutation occur when the insertion or deletion of one or two bse pairs alters the reading frame of the DNA strand.
Frameshift mutations(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
These mutations are characterized by amplification of a sequence of three nucleotides.
Trinucleotide repeat mutations(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
Disease characterized by CGG trinucleotide repeats.
Fragile X Syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.227
This is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems.
Huntington’s disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229
Genetic mutation in Huntington’s disease?
CAG trinucleotide repeats(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229
This disorder is a chronic, slowly progressing inherited genetic disorder characterized by muscle wasting, cataracts, heart conduction defects, endocrine changes and myotonia.
Myotonic Dystrophy(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229
Genetic mutation found in myotonic dystrophy?
CTG Trinucleotide repeats(TOPNOTCH)
A point mutation wherein a single base pair is replaced but codes for the same amino acid, therefore has no effect on the functioning of the protein.
Silent mutation(TOPNOTCH)
An example of point mutation wherein a purine base is replaced by another purine base or a pyrimidine base is replaced by another pyrimidine base.
Transition(TOPNOTCH)
A point mutation wherein a purine is replaced by a pyrimidine or vice versa.
Transversion (V - Valiktad) (TOPNOTCH)
Diseases caused by single gene defects are called?
Mendelian Disorders(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.228
A condition wherein both dominant and recessive alleles of a gene pair may be fully expressed in the heterozygote.
Codominance(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.228
The presence of many allelic forms of a single gene is called _______.
Polymorphism(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.228
This occurs when one gene influences or leads to multiple phenotypic traits.
Pleiotropy(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.228
A phenomenon wherein a single phenotype or genetic disorder may be caused by mutations of several genetic loci or allele.
Genetic heterogeneity Note: compare with pleiotropy(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.228
A transmission pattern of inheritance which is manifested in the heterozygous state, wherein at least one parent of an index case is usually affected, both males and females are affected and both can transmit the condition.
Autosomal dominant (AD)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229 *SEE SLIDE 7.1
This pattern of inheritance occur when BOTH of the alleles at a given gene locus are mutants, wherein the parents are not affected, but offspring have 1 in 4 chance (25%) of being affected.
Autosomal recessive(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229 *SEE SLIDE 7.1
Pattern of inheritance wherein the disorder is transmitted by heterozygous female carriers only to 50% of the sons. An affected male does not transmit the disorder to sons but all daughters are carriers.
X-linked disorders(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.229 *SEE SLIDE 7.2
An autosomal dominant disorder of connective tissues characterized by abnormally long legs, arms and fingers, joint hyperextensibility, pectus excavatum, lens subluxation (Ectopia lentis) and increased risk of aortic dissection. *SEE SLIDE 7.3
Marfan Syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.230
Integral component of elastic fibers defective in Marfan Syndrome.
Fibrillin 1(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.230
Fibrillin 1 is encoded by what gene?
FBN1 gene (chromosome 15q21)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.230
A collection of disorders caused by defects in collagen synthesis or structure, characterized by hyperextensible skin and joint hypermobility, rupture of internal organs and poor wound healing. *SEE SLIDE 7.4
Ehlers-Danlos SyndromesThere are 6 variants to Ehlers-Danlos (nice to know)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.231
This autosomal recessive inborn error of metabolism is characterized by inability to convert phenylalanine to tyrosine, strong mousy or musty odor of urine and sweat, decreased pigmentation of hair and skin, eczema, seizures and mental retardation.
Phenylketonuria (PKU)(TOPNOTCH)
This autosomal dominant disorder is caused by a mutation in the gene that specifies the receptor for LDL, impairing the intracellular transport and catabolism of LDL.
Familial hypercholesterolemia(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.232
Enzyme deficient in classic PKU.
Phenylalanine hydroxylase (PAH)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.234 *SEE SLIDE 7.5
An autosomal recessive disorder of galactose metabolism characterized by jaundice, liver damage, cataracts, neural damage, vomiting and diarrhea.
Galactosemia(TOPNOTCH)
Deficiency of this enzyme can also cause symptoms of phenylketonuria due to decreased synthesis of a cofactor in the conversion of phenylalanine to tyrosine.
Dihydrobiopteridine reductase (DHPR)Enzyme responsible for the reduction of Dihydrobiopterin (BH2) to Tetrahydrobiopterin (BH4).(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.234
Enzyme deficient in galactosemia.
Galactose-1-phosphate uridyltransferase(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.235
Lysosomal storage disease due to deficiency of glucosylceramidase.
Gaucher disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.236
Lysosomal storage disease due to deficiency of B-Hexosaminidase A.
Tay-Sachs disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.236
Lysosomal storage disease due to deficiency of a-Galactosidase A.
Fabry disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.236
Lysosomal storage disease due to deficiency of Sphingomyelinase.
Niemann-Pick disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.236
Lysosomal storage disease common among Ashkenazi Jews characterized by motor weakness, mental retardation, blindness, neurologic dysfunction and death.
Tay-Sachs disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.236
Lysosomal storage disease characterized by accumulation of glucosylceramide in mononuclear phagocytic cells, which enlarge, forming “wrinkled tissue paper” cytoplasmic appearance. *SEE SLIDE 7.6
Gaucher disease(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.238
What do you call the pathognomonic cell characterized by “wrinkled tissue paper” cytoplasmic appearance. *SEE SLIDE 7.6
Gaucher cell(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.238
These disorders result from the accumulation of mucopolysaccharides in many tissues including the liver, spleen, heart, blood vessels, brain, cornea and joints. Affected patients have coarse facial features.
Mucopolysaccharidoses(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.238
Mucopolysaccharidosis characterized by corneal clouding, coronary arterial and valvular depositions, which occurs due to deficiency of a-L-iduronidase, leading to accumulation of dermatan and heparan sulfate.
Hurler syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.239
An X-linked mucopolysaccharidosis which is due to a deficiency of L-iduronate sulfatase. Symptoms are similar to Hurler syndrome, but without corneal clouding.
Hunter syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.239
Glycogen storage disease characterized by hepatomegaly, renomegaly, hypoglycemia, hyperlipidemia and hyperuricemia, leading to gout and skin xanthomas.
von Gierke’s disease (Type I)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.240
von Gierke’s disease is due to a deficiency of what enzyme?
Glucose-6-phosphatase(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.240
Glycogen storage disease characterized by accumulation of glycogen in skeletal muscles leading to painful cramps during strenuous exercise and myoglobinuria.
McArdle syndrome (type V)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.240
Glycogen storage disease characterized by mild hepatomegaly, cardiomegaly, muscle hypotonia, and may lead to cardiorespiratory failure.
Pompe disease (type II)(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.240
Enzyme deficient in McArdle syndrome.
Muscle phosphorylase(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.240
These disorders may result from alterations in the number or structure of chromosomes and may affect autosomes or sex chromosomes.
Cytogenetic disorders(TOPNOTCH)
These disorders may result from alterations in the number or structure of chromosomes and may affect autosomes or sex chromosomes.
Cytogenetic disorders(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.241
It is a term used to describe the presence of two or more populations of cells in the same individual.
Mosaicism(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.242
This refers to a lack of one chromosome of the normal complement (e.g. XO).
Monosomy(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.244
This refers to the presence of three copies of a particular chromosome, instead of two.
Trisomy(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.244
This mechanism occurs due to the failure of chromosome pairs to separate properly during meiosis stage 1 or 2.
Nondisjunction(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.243 *SEE SLIDE 7.7
This mechanism implies transfer of a part of one chromosome to another chromosome.
Translocation(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.243 *SEE SLIDE 7.7
This mechanism involves loss of a portion of a chromosome.
Deletion(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.243
Patients with this syndrome have severe mental retardation, flat facial profile, epicanthic folds, cardiac malformations, increased risk of leukemia, and premature development of Alzheimer’s disease.
Down syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.244
Down syndrome is also called _________
Trisomy 21(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Trisomy 18 is also called ________ syndrome.
Edwards syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Trisomy 13 is also called _________ syndrome.
Patau syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.244
Syndrome characterized by a prominent occiput, low set ears, micrognathia, rocker-bottom feet, renal malformation, mental retardation and heart defects.
Edwards syndrome / trisomy 18(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Syndrome characterized by mental retardation, microcephaly, micropthalmia, polydactyly, cleft lip and palate, cardiac and renal defects, umbillical hernia and rocker-bottom feet.
Patau syndrome/Trisomy 13(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Syndrome characterized by thymic hypoplasia with diminished T-cell immunity and parathyroid hypoplasia with hypocalcemia.
DiGeorge syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Syndrome characterized by congenital heart disease affecting outflow tracts, facial dysmorphism and developmental delay.
Velocardiofacial syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
Deletion of genes from this chromosome gives rise to DiGeorge and velocardiofacial syndromes.
22q11.2Remember mnemonic CATCH22(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.245
The q from 22q11.2 refers to ________.
“Long arm” of chromosome 22.(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.246
Syndrome defined as male hypogonadism that develops when there are at least two X chromosomes and one or more Y chromosomes.
Klinefelter syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.246
Syndrome manifested by a eunochoid body habitus, reduced facial, body and pubic hair, gynecomastia, testicular atrophy, decreased serum testorerone and increased urinary gonadotropin levels. It is the most common cause of hypogonadism in males.
Klinefelter syndrome (TOPNOTCH)Robbins Basic Pathology, 8th Ed p.246 *SEE SLIDE 7.8
Most common chromosomal derangement in Klinefelter syndrome.
47XXY(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.246
Syndrome which results from the partial or complete monosomy of the short arm of the X chromosome.
Turner syndrome(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.247 *SEE SLIDE 7.8
Inheritance associated with mitochondrial DNA.
Maternal inheritance(TOPNOTCH)
Neurodegenerative disease which manifests as progressive bilateral loss of central vision that leads to blindness. This is the prototypical disorder of mutations in mitochondrial genes.
Leber hereditary optic neuropathy(TOPNOTCH)
Inheritance associated with mitochondrial DNA.
Maternal inheritance(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.247
An epigenetic process wherein certain genes are differentially “inactivated” during paternal and maternal gametogenesis.
Genomic imprinting(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.252
This refers to transcriptional silencing of the maternal allele.
Maternal imprinting(TOPNOTCH)Robbins Basic Pathology, 8th Ed p.251