Genetic Disorders Flashcards
Down syndrome newborn clinical manifestations
hypotonia flat facial features enlarged/protruding tongue small nose upward slant of eyes simian crease abnormally shaped ears hyper flexibility extra space b/w first and second toe brush field spots on iris
Down syndrome adult clinical manifestations
multiple cardiac defects multiple intestinal malformations growth impairment vision abnormalities hearing loss recurrent respiratory infections behavioral issues memory loss w/increased risk of Alzheimer's at an early age
Down syndrome increased risk
maternal age
Klinefelter syndrome clinical manifestations
50% develop gynecomastia
may have: impaired psychosocial skills, impaired higher language skills, increased risk of Non-Hodgkin’s lymphoma/leg ulcers/lupus
will have: small testes, abnormally low sperm count, decreased sperm testosterone, abnormal arm and leg length, increased risk of male breast cancer and pulmonary disease
Klinefelter Genetics
XXY
Turner syndrome clinical manifestations
hearing loss hypothyroidism autoimmune disease/ autoimmune thyroiditis elevated liver enzymes primary amenorrhea osteoporosis renal structure abnormalities vision/ocular abnormalities diabetes hyperlipidemia HTN cardiac structure abnormalities aortic dissection increased CV mortality
Turner syndrome physical characteristics
female appearance short, wide chest prominent neck skin folds usually sterile/low estrogen small breasts normal mental development
Turner syndrome genetics
XO
Cystic fibrosis clinical manifestations
thick mucus buildup in lungs and pancreatic ducts
failure to thrive impaired growth in kids chronic pulmonary infections/colonization of pseudomonas aeruginosa nasal polyps epistaxis sinusitis chronic cough hemoptysis abnormal lung parenchyma cor pulmonale pancreatitis steatorrhea CF-related DM biliary cirrhosis liver damage portal HTN
Cystic Fibrosis males
98% infertile due to absence of vas deferens
Cystic Fibrosis genetics
autosomal recessive
CFTR gene
F508 mutation most common
Cystic Fibrosis pathophysiology
change in chloride and water transport across membranes
ions stay intracellularly so water not getting into mucus
PKU clinical manifestations
severe mental retardation due to excess phenylalanine
- -impairs brain growth
- -impairs myelination
- -impairs NT synthesis
PKU genetics
autosomal recessive
PKU treatment
dietary restriction of phenylalanine + pharmacotherapy
SCID clinical manifestations
children prone to develop severe infections due to deficient T and B cells
commonly fatal w/in one year
SCID genetics
X-linked genes (multiple)
IL2RG defect
SCID treatment
gene therapy
hematopoietic stem cell transplant
SCID dx
look at newborn biomarkers for naive T cells
Alzheimer’s disease clinical manifestations
memory deficits (recent events) language changes --verbal disfluency --anomia --reduced vocabulary --diminished comprehension --circumlocution visuospatial skills --misplace items --worsening navigation skills Reduced insight into self-decline apraxia/dyspraxia loss of executive fan mild depression/psychosis changes in olfactory fan loss of sleep combative
Alzheimer’s disease early onset genetics
Autosomal dominant
APP gene
PSN1 gene
PSN2 gene
Alzheimer’s disease late onset genetics
Many genes
APOE epsilon 2 (decreases risk)
APOE epsilon 3 (no affect on risk)
APOE epsilon 4 (increases risk of AD)
Late onset Alzheimer’s disease genetic testing
not recommended, many genes involved and outcome isn’t certain
Early onset Alzheimer’s disease genetic testing
Can be tested for 3 genes if desired, still won’t predict age of onset
Alzheimer’s disease pathogenesis
amyloid plaques
neurofibrillary tangles
lose synaptic connections
kill neurons
Huntington’s disease clinical manifestations
PROGRESSIVE
Chorea gait abnormalities slow eye movements (lose smooth movement) irritability anxiety depression disrupted social relationships paranoia aggression delusions loss of insight inflexibility memory loss impaired judgement weight loss/cachexia
Huntington’s disease genetics
autosomal dominant
Huntingtin gene/protein
juvenile HD almost always inherited from father
White people, mid-life onset
Huntington’s Disease and CAG repeats
higher CAG repeats=earlier onset/greater severity
negative <35
positive >40
Neurofibromatosis type 1 clinical manifestations
cafe au lait macules freckling lisch nodules cutaneous/plexiform/nodular neurofibromas optic gliomas neoplasms bony abnormalities neurologic abnormalities ADD mental retardation learning disability seizures macrocephaly HTN peripheral neuropathy
Neurofibromatosis type 2 clinical manifestations
neurologic lesions bilateral vestibular schwannomas--> lead to hearing loss, tinnitus, balance dysfunction meningioma spinal tumors peripheral neuropathy schwannomas of other cranial nerves ocular lesions skin lesions
Neurofibromatosis type 1 genetics
autosomal dominant
50% inherited, 50% de novo
Neurofibromin is tumor suppressor gene
Neurofibromatosis type 2 genetics
Autosomal dominant
merlin/schwannomin are tumor suppressor genes
Neurofibromatosis 1 and 2
NF 1 more common
Genetic testing not widely available, look at family hx
Polycystic Kidney Disease Clinical Manifestations
Bilateral renal cysts (quadruple size of kidneys) cysts can scar and replace normal structure, affecting kidney fxn Renal lithiasis Hematuria Proteinuria flank pain UTI renal infection HTN (disturbances of renal perfusion) ESRD
ESRD–end stage renal disease
loss of normal renal tissue/death of renal tubular cells
Polycystic Kidney Disease affects on other systems
Polycystic liver disease Pancreatic cysts Seminal vesicle cysts Intracranial aneurysm Diverticulosis/diverticulitis Dilation of aortic root cardiac valve abnormalities
Polycystic Kidney Disease genetics
Usually autosomal dominant
PKD1 (85% of disease)
PKD2 (15% of disease)
some people have both
VERY RARELY autosomal recessive
PKD1
more severe symptoms and earlier onset
ESRD progression by age 60 in 50% of pts
Polycystic Kidney Disease genetic testing
available
all kidney donors should be thoroughly tested
Hereditary hemochromatosis clinical manifestations
hepatomegaly elevated liver enzymes fibrosis/cirrhosis increased risk of hepatocellular carcinoma DM arthropathy heart disease hypogonadism amenorrhea increased infection hyper pigmented skin
Reversible clinical manifestations of hereditary hemochromatosis
cardiomyopathy arrhythmia abdominal pain hepatomegaly increased liver enzymes skin hyperpigmentation infection
Irreversible clinical manifestations of hereditary hemochromatosis
cirrhosis hepatocellular carcinoma hypogonadism DM hypothyroidism arthritis
Hereditary hemochromatosis genetics
Autosomal recessive
variable penetrance
HFE gene mutation
- -C282Y
- -H63D
Hereditary Hemochromatosis gender distributions
more common in men
if women develop, usually at later age
Hereditary Hemochromatosis iron absorption/storage
iron absorption not regulated by amount of iron stores
increased iron stored in liver, pancreas, skin, heart, pituitary gland, causes end organ damage
Hereditary Hemochromatosis treatment
remove blood
Hemophilia clinical manifestations in newborn
intracranial hemorrhage w/seizures
increased bleeding w/circumcision
Hemophilia clinical manifestations in kids (usually dx by age 6)
abnormal bleeding during procedure/injury
excessive bruising, hematomas, hemarthroses