Genetics Flashcards
Marfan Syndrome
Tall, long arms, pectus excavatum, scoliosis, lens dislocaiton. Defect in Fibrillin-1. Aortic Root Dilatation is the most severe complication.
Ehlers-Danlos Syndrome
Normal stature, scoliosis, joint laxity, aortic root dilatation. Collagen disorder.
Duchenne Muscular Dystrophy
Calf pseudohypertrophy
Gower Sign
Dx with genetic testing
Xlink recessive
Osteogenesis imperfecta
90% Autosomal dominant, type I collagen defect
Mild-Moderate type: easy fractures, blue sclera, gray teeth, joint hypermobility, conductive hearing loss
Lethal type:in utero/neonatal fractures, pulmonary failure
Tay-Sachs Disease
B-hexosaminidase A deficiency, autosomal recessive, Ashkenazi Jews.
Hypotonia, feeding difficulty, Hyperreflexia, Cherry Red Macula
2-6mo age of onset
Niemann-Pick Disease
Sphingomyelinase Deficiency, autosomal recessive, Ashkenazi Jews.
Hypotonia, Feeding difficulties, HSM, Areflexia, Cherry red macula.
2-6mo age of onset.
Fragile X Syndrome
Neurodevelopmental problems, prominent forehead, large ears, elfin like face, macroochidism.
X linked CGG expansion in FMR1 gene.
Females will have varying levels of intellectual disability
Edward Syndrome
Trisomy 18
IUGR, microcephaly, VSD, overlapping fingers, rocker bottom heels, micrognathia, low set ears, prominent occiput, renal dysfunction, limited hip abduction.
95% die in the first year of life.
Cri-du-chat
5p deletion
cat-like cry, prominent metopic suture, hypertelorism, microcephaly, intellectual diability.
Patau Syndrome
Trisome 13
Cutis aplasia, holoprosencephaly, microphthalmia, cleft lip and palate, polydactyly, cardiac defects, renal defects, omphalocele, and rocker bottom heels.
Choanal Atresia
Incomplete recanalization of the nasal passages. Infants will be cyanotic at rest, improve when crying, and have difficulty feeding.
This can be a sole finding or present with CHARGE syndrome
CHARGE Syndrome
Choloboma (eye defect), Heart Defects, Atresia chonae, Retardation, Genitourinary problems, Ear Abnormalities/Deafness
Cystinuria
stones since childhood, FMH of nephrolithiasis, hexagonal crystals in urine.
impaired transport of cystine.
+ cyanide-nitroprusside test
Common Variable Deficiency
Recurrent infections starting in middle childhood
markedly decrease IgG, moderately decrease IgM and IgA.
Normal T and B cell counts
Tx: immunoglobulin replacement.
Congenital lymphedema
Lymphatic network dysgenesis occurs in Turner Syndrome
NF1
NF1 suppressor gene mutation on chromosome 17, encodes neurofibromin.
Cafe au lait spots, freckling, multiple neurofibromas, Lisch nodules. Can have low-grade optic pathway glioma.
NF2
NF2 suppressor gene on chromosome 22, encodes merlin.
Bilateral acoustic neuromas.
Genes/Conditions related to Pheochromocytoma
NF1 - Neurofibromatosis
RET - MEN2 (Parathyroid, pheo, medullary thyroid)
VHL - von Hippel Lindau
Li-fraumeni syndrome
P53 mutation
sarcomas. breast cancer, adrenal carcinoma, gliomas, medulloblastomas
Chronic granulomatous disease
X linked most of the time
recurrent infections with catalase positive organisms (S. aureus, serratia, aspergillus)
Decreased NADPH oxide activty
X linked agammaglobulinemia
Decreased IgG, recurrent sinupulmonary infections and bacteremia.
Leukocyte adhesion deficiency
Decreased neutrophil chemotaxis, recurrent infections with S. aureus and other skin flora but the infection sites often have minimal pus.
Hyper IgE Syndrome (Job Syndrome)
Recurrent abscesses and pulmonary infections. Broad nose and scoliosis. Autosomal dominant.
Fanconi Anemia
DNA repair defect
Short stature, hypoplastic thumbs, hypo/hyperpigmented macules, genitourinary malformations
Pancytopenia, positive chromosomal breakage
Tx: stem cell transplant
Selective IgA deficiency
Most common primary immunodeficiency
recurrent sinopulmonary and GI infections
associated with asthma, eczema, celiac
Anaphylaxis to blood transfusions (antibodies to IgA)
Neonatal polycythemia
HCT >65%
Intrauterine hypoxia or increased blood transfusion
Resp distress
IV fluids + glucose
Landau-Kleffner syndrome
Regression of language skills due to severe epilepsy
Tuberous sclerosis
Seizures, cognitive defects, autistic features with skin findings such as hypopigmented macules, angiofibromas, and forehead plaques.
Rett Syndrome
Neurodevelopment disorder occuring mainly in girls. Normal development and then regression of speech, loss of purposeful hand movements, gait abnormalities, and seizures.
Lesch-Nyhan Syndrome
Hypoxanthine and uric acid accumulation
Infants exhibit hypotonia and delayed milestones
Eventually, become hypertonic and exhibit self-mutilating behavior
Alport Syndrome
Collagen IV mutation Cant see cant pee cant hear a bee Starts with isolated hematuria, then sensorineural hearing loss, and vision loss. Longitudinal splitting of GBM X linked mostly
Wiskott-Aldrich Syndrome
Impaired cytoskeleton changes in leukocytes and platelets. Eczema, Microthrombocytopenia, recurrent infection.
Xlinked
Stem cell transplant
Hereditary Hemochromatosis
Hyperpigmentation, arthralgia, chondrocalcinosis, elevated liver enzymes that progress into cirrhosis, DM2, hypogonadism, hypothyroid, cardiomyopathy, increased susceptibility to Listeria, Vibrio, and Yersinia.
