DETECTION OF INHERITED DISEASES Flashcards
A DNA sequence change that is present in a relatively small proportion of a population is a ___
mutation
___ are casually considered mutations that do not severely affect phenotype.
Polymorphisms
located within genes or outside of genes.
Sequence polymorphisms
useful for mapping disease genes, determining parentage, and identity testing.
Benign polymorphisms
can have offsetting phenotypes.
Balanced polymorphisms
do not change the primary DNA sequence.
Epigenetic alterations
usually alterations of cytosine in CpG islands; mostly downregulates RNA transcription.
DNA methylation
selectively inactivates chromosomal regions (e.g., X chromosome inactivation).
Genomic imprinting
Diseases with genetic components are often referred to as ___ (“born with”) diseases.
congenital
two or more genetically distinct populations of cells from one zygote in an individual;
Mosaicism
different zygotes in an individua two or more genetically distinct cell populations froml), results from mutation events affecting somatic or germ cells.
Chimerism
via blood transfusion, organ, stem cell, and bone marrow transplantation.
Artificial chimerism
via trans placental passage of second cell line
Twin/multiple gestations
via fusion of two fertilized zygote
Tetragametic
is a diagram of the inheritance pattern of a phenotype of family members.
pedigree
alternative forms of a gene that occupy a specific locus on a specific gene
Allele
having two different alleles for a given gene
Heterozygous
having two identical alleles for a given gene
Homozygous
pattern of inheritance that corresponds to the equal, distinct, and simultaneous expression of two different alleles
Codominance
describes a trait that is expressed both in homozygous and heterozygous form
Dominant
describes a trait that is only expressed in homozygous form and is masked in heterozygous form
Recessive
heterozygous individual who does not display symptoms of a recessive genetic disorder but can transmit the disorder that corresponds to the equal, distinct, and simultaneous expression of two different to his or her offspring
Carrier
in humans, the 22 pairs of chromosomes that are not the sex chromosomes (XX or XY)
autosomal chromosome
pattern of dominant inheritance that corresponds to a gene on one of the 22 autosomal chromosomes
autosomal dominant
pattern of recessive inheritance that corresponds to a gene on one of the 22 autosomal chromosomes
autosomal recessive
pattern of inheritance in which an allele is carried on the X chromosome of the 23rd pair
X-linked
pattern of dominant inheritance that corresponds to a gene on the X chromosome of the 23rd pair
X-linked dominant:
pattern of recessive inheritance that corresponds to a gene on the X chromosome of the 23rd pair
X-linked recessive
a disease that induces tumor formation within the nervous system that leads to skin and skeletal deformities.
Neurofibromatosis type I
characterized by the chronic accumulation of a thick, tenacious mucus in the lungs and digestive tract; blood disorder sickle-cell anemia, the fatal neurological disorder Tay–Sachs disease, and the metabolic disorder phenylketonuria.
Cystic fibrosis (CF)
transmission pattern involves genes located on the X chromosome of the 23rd pair.
X-linked
Trisomy 21, 47,XY, + 21
DOWN SYNDROME
Trisomy 18 (47,XY,+18)
EDWARD SYNDROME
Trisomy 13, 47,XY, +13
PATAU SYNDROME
47XXY karyotype in 82% of cases.
KLINEFELTER SYNDROME
45, X and variants – X0
TURNERS SYNDROME
XYY syndrome (47,XYY)
JACOB’S SYNDROME
47,XXX; 48,XXXX
MULTI X FEMALES
