Genetics Final

• aka: inbreeding
• reproduction between closely related people
• the closer the relative is related to the proband/consultand the more likely it is that they share a common genotype

• immediate relative
• 1 position away on the descent line

2 positions away on the descent line

3 positions away on the descent line

• aka: polygenic inheritance
• multiple genes determine a single trait
• the more genes involved the more continuous the variation

• multifactorial
• nature vs. nurture
• monozygous tins show substantial evidence for a genetic basis to intelligence

• a correlation between phenotype and genotype
• H=1: populations phenotypic variance due entirely to genotype
• H-0: variance due to environment

predict the futrue based on the past using emperical risk figures

• heritability
• correlation between specific DNA marker sequence
• emperical risk figures

• pedigrees
• twin studies
• heritability
• DNA associative studies
• emperical risk figures

• 1. family risk is higher than the general population
• 2. family risk drops the further away you are
• 3. recurrent risk higher if multiple family members are affected
• 4. risk often related to severity
• 5. may exibit threshold expression
• 6. prior history useful to determine approx recurrant risk
• 7. primary relatives risk = square root of the populations risk

• very difficult to explain at molecular level
• some degree of continuous variability, heredity, and familial aggregation (autosomal dom. with reduced penetrance)
• envrionment plays a role in expression
• everything is somehow genetic

to address the complex issue of how genes are distributed in populations

• what is the genotype of a typical person
• how common are carriers
• what determines pop frequency of disease
• what factors effect frequency of genes in pop

• 1. gene poop
• 2. allelic frequencies
• 3. genotypic and phenotypic frequencies

sum total of all alleles in the reproductive gametes from members of a mendillian population

• the state of balance between allelic frequencies
• 1. no mutations
• 2. no migration
• 3. no assortative mating
• 4. no selecion
• 5. no genetic drift

1= p²+ 2pq+ q²

• O is recessive
• A and B are co-dominant

• produces human leukocyte antigen
• genes are inherited as a group-haplotypes
• certain HLA types are associted with disease

high risk of ankylosing spondylitis

a protein coded for by a gene

by binding to specific cell surface molecules coded for by genes

• when cells lose control of their cell cycle
• some run in families meaning cancer is a disease of genes

• promote cell division
• form oncogenes- promote uncontrolled cell division

inhibit cell division

• carcinogenesis requires multiple tumore suppresor gene mutations
• two-hit model

• most cancers
• both TSGs must be mutated for cancer

inherit one bad TSG, other one mutates

released from restraints on # of mitotic cells

sporadic

• if you have BRCA1 and 2
• have 60-80% risk of developing cancer

• reproduction is unpredictable
• only recieve mitochondria from moms oocyte- mitochondrial genes are maternal
• distrobution of variant ones in body is unpredictable
• mitochondrial disorder inheritance is very hard to predict

• there is diversity in the ability of a person to process or metabolize nutrients
• nutrients can alter gene expression
• nutrients may alter compounds that affect other metabolic pathways
• variations in adsoprtion ability
• nutrients are a form of nruture

a collaborative effort between health profesionals

to expose patients to methods of prevention, aboidance, and amelioration of these disorders

25%

50%

25%

slight increase over general populations

• usually < 10%
• look at emperical risk figures

• what is the exact diagnosis
• know facts/family history (pedigree)

• Family: history
• G: groups of congenital abnormalities
• E: extreme/exceptional presentation
• N: neurodevelopmental delay/degeneration
• E: extreme/exceptional pathology
• S: surprising lab values

• 1. late maternal age (35+)
• 2. prior child with chromosomal defect
• 3. history of miscarriage
• 4. known defect in parent
• 5. family history of genetic disease in high risk ethnic group

• soon available
• not cures

• DNA analysis and repair
• disruption of defective genes

autosomal recessive

autosomal dominant

autosomal dominant

autosomal dominant

autosomal dominant

autosomal dominant

autosomal dominant

autosomal recessive

autosomal recessive

autosomal recessive

autosomal recessive

autosomal co-dominant inheritance (Aa- semi affected)

autosomal co-dominant inheritance (Aa= semi affected)

male with female-like qualities

female with male-like qualities

x-linked recessive

x-linked recessive

x-linked recessive

x-linked recessive

x-linked recessive

• multifactorial linheritance
• scoliosis- multiple forms, AIS most common
• common: females have larger curves than males
• autosomal dominant with reduced penetrance
• penetrance: 60%

• multifactorial inheritance
• condition of pars interarticularis, common source of LBP
• common
• autosomal dominant with reduced penetrance
• penetrance: 40%

• multifactorial inheritance
• displacement of the femoral head outside the acetabulum prior to or slightly after birth
• common in caucasians
• autosomal dominant with reduced penetrance
• shown to run in families, more in females

• multifactorial inheritance
• autoimmune spondyloarthopathy condition
• chronic, painful, progressive inflammatory arthritis affecting primary spine and SI joint leading to fusion
• associated with HLA-B27
• familial aggregation and genetic predisposition

• multifactorial inheritance
• embryonic failure to fully close the developing tube
• listed as autosomal dominant
• 1 in 1,000 people
• recurrent risk is 4% in siblings

• multifactorial inheritance
• substantial narrowing of the stomach pylorus
• significant hypertrophy and hyperplasia of the pylorus
• not uncommon: 1 in 400
• autosomal dominant with reduced penetrance
• threshold trait- will occur when multiple factors cause an anomalous variation in the pylorus

• multifactorial inheritance
• developmental failure of fusion of maxillary process and frontal process
• not uncommon: 1 in 700
• autosomal dominant with variable expressivity/severity

• previous child: 2%
• parent had it: 6%
• previous child and parent had it: 15%

• multifactorial inheritance
• congenital anomalies characterized by a foot that is twisted in and down
• colloquial term for a collection of skeletal deformities that include talipes equinovarus
• autosomal dominant with reduced penetrance

• multifactorial inheritance
• common and on the rise: 1 in 3
• type 1= autoimmune, type 2= insulin resistance

• sibling: 40%
• child: 33%

• when of unknown origin it is deemed essential which is about 95% of cases
• polygenic because there are a number of genes that contribute to it

• application of selective principles upon mankind by mankind
• positive: encouraging those with desirable traits to reproduce (Hitler)
• negative: discouraging those with undesirable traits from reproducing