genetic syndromes Flashcards
fragile X syndrome
- x linked dominant trinucleotide repeat CGG (chin, giant gonads) in the FMR1 gene
- loss of function of FMR1 gene on X chromosome (hypermethylation)
- features prominent after puberty
- long narrow face
- prominent chin and forehead
-hyperlaxity of joints
-developmental delay
klinefelter
- 47 XXY
- tall stature
- gynecomastia
- small testes
- infertility
hereditary fructose intolerance
aldolase B
- vomiting and hypoglycemia
-20 - 30 min after digestion
tay sachs disease
- auto recessive
- neurodegenerative disease
- lysosomal function disease (onion skin lysosomes)
- beta hexosaminadase A deficiency (no amenities for hicks)
- GM2 ganglioside (glycoplipid component of cell membranes) accumulation (2 gangsters) toxic to neurons
- regression of motor skills
- bright red fovea centralis - red cherry macula
- NO hepatosplenomegaly
- onset 6 months
niemann pick disease
-accumulation of sphingomyelin (toxic to brain and spinal cord)
-cherry red macula spots in eyes
-hepatosplenomegaly*
-lysosomal storage disease
-foam cells, lipid laden macrophages*
- neurodegeneration - loss of developmental milestones
heteroplasmy
-variable degrees of severity due to amount of mitochondrial DNA inherited
genomic imprinting
- inactivation of either paternal or maternal alleles
- prader willi and angelman syndrome
polygenic diseases
SHIT AGE
- schizophrenia
- hypertension
- ischemic heart disese
- T2D
- androgenic alopecia
alkaptonuria
autosomal recessive
deficiency of homogentisic acid dioxygenase
- deposits of blue sclera and blue ears
- ankylosis, motion restriction
Autosomal dominant Disease’s
Von von Als rb MEN
Tubes and spheres and Huntington’s
Marfans elhlers Dan
Nf 1/2 don’t FAP too much
Autosomal dominant yes this song is clutch
Von hippo lindau
Von willibrand
Amyolateral sclerosis
Retinoblastoma
Men
Tuberous sclerosis
Hereditary spherocytosis
Huntington’s
Marfans
Ehlers danlos
Neurofibromatosis 1/2
Familial adenomatous polyposis
inheritance pattern of neurofibromatosis
autosomal dominant
achondroplasia
mutation in fibroblast growth factor receptor 3
Mutation in branch chain alpha keto acid
Maple syrup urine disease
tay sachs and Niemann pick genetic inheritance pattern
autosomal recessive
diseases with cherry red spot macula
tay sachs and Niemann pick
accumulation of spingomyelin
nieman pick disorder
lysosomal storage disease with hepatosplenomegaly
niemann pick, gaucher,
lysosomal storage disorders are also
neurodegenerative diseases - motor regression
hexosaminidase A deficiency
tay sachs
gaucher disease inheritance
autosomal recessive
accumulation of glucocerebroside
gaucher disease
tissue paper macrophages
gaucher disease
fabry’s disease inheritance
x linked recessive
accumulation of ceramide trihexoside
fabry disease
deficiency in alpha galactosidase
fabry disease
clinical signs of fabry’s disease
peripheral neuropathy, angiokeratomas (benign capillary tumors), hypohydrosis (decreased sweating)
late complication of fabrys disease
heart and kidney failure
osteogenesis imperfectica
type 1 collagen disorder
alport syndrome
type IV collagen disorder
CTG trinucleotide repeat
myotonic dystrophy type 1
platelet count in wiscott Aldrich syndrome
decreased
platelet count in hyper IgE
normal
failed obliteration of the allantois can lead to
patent urachus (urinate out of belly button)
Tall stature, gynecomastia, azoospermia
Klinefelter
trisomy 13
patau syndrome - midline defects
Loss of paternal X chromosome
Turrner syndrome
heteroplasmy
responsible for clinical variability of mitochondrial diseases (during mitosis, mitochondria are randomly distributed between daughter cells)
genetic imprinting
selective inactivation of maternal or paternal alleles, seen in prader will syndrome vs angel man syndrome
deficiency of glycogen debranching enzyme
cori disease
tuberous sclerosis
- autosomal dominant
- renal angiomyolipomas, subependymal hamartomas in brain, seizures, cognitive disability
rare congenital vascular disorder characterized by facial port wine stain and leptomeningeal capillary venous malformation
sturge-weber
AFP and AchE in down syndrome
low AFP, normal AchE
large ears, long face, macroorchidism
fragile X syndrome
inability to convert phenylalanine to tyrosine
phenylketonuria
cystic fibrosis
- most common mutation is 508
- causes abnormal protein folding leading to proteasome degradation and decreased number of transmembrane proteins
Activating mutation in FGFR3
Achondroplasia, inhibits cartilage growth, auto dominant
Pes cavus
High feet arches
Kyphoscoliosis, pes cavus, bilateral lower extremity ataxia, loss of proprioception and vibration sense
Friedreich ataxia
glycogen debrancher enzyme deficiency
cori disease
inheritance of G6PD
x linked recessive, causes acute hemolysis after exposure to certain medications or fava beans
urine with sweet smelling odor
maple syrup urine disease - branch chain keto acid dehydrogenase deficiency - restrict leucine, isoleucine, and valine
androgen insensitivity syndrome
happens in XY males, no internal development because of loss of the androgen receptor, so can’t differentiate into male sex organs. absent internal organs and female external organs, diagnosed in adolescence due to primary ammenorhea
variable expressaility
a distinct genotype has many different phenotypes ex. marfans
interactions between multiple genes that combine to create a new phenotype or mask/modify a phenotype
achondroplasia
FGFR3 mutation, macrocephaly, frontal bossing, midface hypoplasia, trident hand, shortened limbs, genu varum,
