Genetics Flashcards
Embryogenesis
Post fertilization zygote divides, and three days becomes the morula
Blastocyst
Center cavity of morula
Embryo
Cells from inner cell mass
Trophoblast
Cells from the outer layer
Turns into placenta
For the first six weeks any loss of cells inside the inner mass becomes this
Congenital deformity
First trimester
Expensive cell division
Cell migration, apoptosis
Cell to cell interaction
Skeleton and bones done by week 6 to 7
Critical -Environmental factors can cause developmental defects
Fetal life
Nine months or 36 to 40 weeks
No true development after first trimester only growth, Except for the brain and sexual characters and function
Functional fetal cells versus adult
Liver alpha-fetoprotein as major plasma proteins adult liver, secretes albumin
Lung surfactant in fetus is different than in adult life because the fetus is not breathing the surfactant is not fully formed
Causes of congenital defects
Chemical teratogens- thalidomide, alcohol,
Microbial teratogens- virus, bacteria, protozoal, parasites
indirect effect from the mothers, exhaustion or weakening, low body weight premature delivery
Direct effect- secondary to transplacental passage to fetus
Down syndrome
Autosomal
Trisomy 21
One in 20 births mother age over 40 years
Mental - early onset Alzheimer’s, 40 years old
Simian crease
Clinodactyly
Predisposition to leukemia and infections
Atlantoaxial instability related to manual therapy, soccer horse riding
Neck surgery -contraindicated
Turner’s syndrome
Monosomy x
No Y chromosome
Short stature
Heart-shaped face
Neck webbing
Heart disease coarctation of aorta
Reproductive system, infantile, sexual characteristics, no puberty
Cubitus valgas
Klinefelter syndrome
Phenotypical makes XXY
no secondary sex characteristics
Infertility
Testicular atrophy
Gynecomastia
Female like hips
Marfan syndrome
Autosomal dominant disorder
Structural protein deficit, febrillin
multisystemic condition
Slender skeleton
Elongated head, dolichocephalic
Heart defects
Aortic aneurysms
Floppy mitral valve
Cystic fibrosis
Recessive disease
1/25 are asymptomatic carriers of the gene
Viscid mucus obstructs lumen of organs
Exocrine, secretions, are thick
can cause malnutrition food, not digested properly
Bronchi and lungs have hyper viscosity of mucus lead to infection- intussusception steatorrhea
Increased salt in sweat
Salt does not get reabsorbed
Hemophilia
Hemorrhagic disorder linked to mutation of genes that code for coagulation factor VII or IX
Factor VIII def= hemophilia A, mild, moderate, or severe presentation
Factor IX def= hemophilia B, always severe
Bleeding may be spontaneous, or after minor trauma
hemarthrosis- joint deformity is common
Death post cerebral bleeding was common
Muscular dystrophy
Genetic disease
Progressive weakness, gradual loss of strength
Symmetrical wasting and effects, heart, and involuntary muscles
Elevated CPK creatine phosphokinase
(Muscle cell injury)
Types of muscular dystrophy
Duchennes- pseudohypertrophic 50% of all cases
Beckers - benign pseudo hypertrophic
Facioscapulohumeral - landouzy dejerine
Limb girdle
Osteogenesis imperfecta
Autosomal dominant disease
Parent is a carrier of the gene spontaneous mutation
Type one collagen is found in ECF matrix of bone skin tendon
Osteogenesis imperfecta effect on bones
Defect in bone modeling
Then cortex of long bones, small volume of cancellous bone
Fractures in utero and deformities at birth
Joint hypermobility
Hearing impairment due to auditory bone deformity
Osteogenesis imperfecta effect on skin
Thin skin bruise easily, some blue gray sclera
Diagnosis of osteogenesis imperfecta
Skin biopsy of collagen
X-rays for fractures
Therapy application for osteogenesis imperfecta
Fracture prevention
May need orthosis or intramedullary rods
Gentle ROM
rotational forces are contraindicated
