peds13 Flashcards
transient hyperammonemia of the newborn
self-limited; may present in premature infants in the first few days of life; aggressive treatment is required to prevent neurologic sequelae
most common urea cycle defect
OTC def
how is OTC def inheritied
x-linked recessive and therefore males more severely affected
clinical features
vomitting and lethargy; begins at onset of protein ingestion
dx of OTC def
elevated urine orotic acid, decr serum citrulline, and increased ornithine; also liver biopsy
management of OTC def
low-protein diet; liver transplant may be necessary
galactosemia
glactose-1-phosphate uridyltransferase def
galactosemia should be suspected when
any newborn with hepatomegaly and hypoglycemia
clinical features of galactosemia
begins after newborn feeds a cow’s milk based formula or breastfeeds for the first time; vomitting, diarrhea, and FTT; hepatic dysfunction and hepatomegaly; cataracts, RTA
dx of galactosemia
non-glucose reducing substance in urine tested by Clinitest; confirmation fo enzyme def in RBCs; prenatal and newborn screenign are available
management of galactosemia
galactose free diet
prognosis of galactosemia
good, with normal intelligence if the disorder is treated earl; mental retard if detected late; ovarian failure in females; E coli sepsis in early infancy
hereditary fructose intolerance
fructose-1-phosphate aldolase B def; begins after intro of fruit
symptoms of hereditary fructose intolerance
severe hypoglycemia, vomitting, diarrhea, FTT, and seizures
management of hereditary fructose intolerance
avoidance of fructose, sucrose, and sorbitol
organomegaly and metabolic acidososi
think glycogen storage diseae
vonGierke’s disease (GSD type 1)
G6Pase def;hypoglycemia, hepatomegaly; metabolic acidosis, hypertriglyceridemia, and enlarged kidneys
management of GSD type 1
frequent feeding with complex carb diet
risk of GSD type 1
patients at incr risk for hepatocellular carcinoma
pompe’s disease (GSD type 2)
alpha glucosidase def; muscular weakness and cardiomegaly, hepatomegaly
when do FAO def present?
during acute illness or fasting, when Fas would be used as energy
clinical features of FAO def
non-ketotic hypoglycemia; hyperamonemia; myopathy and cardiomyopathy
most common FAO defect
medium chain acyl-coA dehydrogenase def
dx of medium chain acyl-coA dehyd def
mass spectrometry to detect elevated amts of medium chain fatty acids
management of FAO def
freq feeding with high carb, low-fat diet and carnitine supplementation during acute episodes
when should mitochondrial dz be suspected?
when a common disease has an atypical presentation or if a disease involves 3 or more organ systems
Kearns-sayre syndrom
mitochondrial disorder; opthalmoplegia, retina pigment issues, hearin gloss, heart block, and neurodegen
MELAS
mitochondrial encephalopathy lactic acidosis, and strokelike episodes
dx of mitochondrial diseases
tissue biopsy revealing abnormal mitochondria
examples of lysosomal storage diseases
tay sachs, gauchers, niemann-pick, metachromatic leukodystrophy, hurler, hunter, sanfilippo, morquio
tay sachs
hexosaminidase A def; hyperacusis (incr sens to sound); macrocephaly, cherry-red macula; severe developmental delay, blindness, seizures
diff between infantile onset and juvenile or adult onset tay sachs
infant begins before age 2; juvenile does not have cherry-red macula
dx of tay sachs
decreased hexosaminidase A activity in leukocytes or fibroblasts
prognosis of infantile tay sachs
death by 4 years
prognosis of juvenile or adult onset tay sachs
degeneration into a chronic debilitiated state
gaucher’s disease
glucocerebrosidase def; most common gangliosidosis
features of gaucher’s disease
erlenmeyer flask shape to the distal femur; mortality by 4 yo; enzyme replacement therapy is management
Neimann-pick disease
sphingomyelinase def; progressive neurodegen, ataxia, seizures, cherry-red macula, hepatomegaly; death by 4 yo
metachomatic leukodystrophy
neurodegen; caused by arylsulfatase A def; ataxia, seizures, progressive mental retard; death by 10-20 yo
what are mucopolysaccharidoses
lysosomal storage disorders in which glucoseaminoglycans accumulate in multiple organs
dysostosis multiplex
bony abnormalities seen in mucopolysaccharidoses
Hurler syndrome
most severe mucopolysaccharidosis
clinical features of Hurler syndrome
developmental delay, kyphosis; progressively coarsened facial features; corneal clouding
management of hurler syndrome
early bone marrow transplant to prevent neurodegen
prognosis of hurler’s
death by 10-15 yo
dx of hurler’s syndrome
dermatan and heparin sulfates in the urine and decrease alpa L iduronidase enzyme activitiy in leukocytes and fibroblasts
Hunter syndrome
x-linked recessive; corneal clouding absent even though it is a mucopolysaccharidosis
features of hunters syndrome
hepatosplenomegaly, hearing loss, “a hunter needs sharp eyes” so no corneal clouding
diagnosis for hunter
same as for hurler; dermatan and heparin sulfates in the urine and decrease alpha L iduronidase enzyme activity in leukocytes and fibroblasts
prognosis for hunters
patients die by age 20
examples of mucopolysacchidoses
hurler, hunter, sanfillipo, morquio
sanfilipo syndrome
rapid and severe mental and motir retardation
morquio syndrome
differs from other mucopolysaccharoidosis in that mental retard is absent; severe scoliosis leading to cor pulmonale results in death by 40 yo
porphyrias
defects in heme pigment biosynthesis; leads to elevated serm porphyrins, which leads to skin photosensitivity, neuro and abdominal symptoms
clinical features of porphyrias
episodic and precipitated by drugs, hormonal surgses, or poor nutirition; neuro, GI (colicky abdom pain), autonomic instability (tachy, sweating)
dx of porphyrias
increased seryn and urine porphobilinogen
management of porphyria
IV glucose, correction of electrolyte abnormalities, and avoidance of fasting and precipitating drugs
wilson’s disease
defect in copper excretion; causes copper deposition initially in the liver, then followed by brain, eyes and heart
when do clinical features of wilsons disease develop?
between 2 and 50 yo
what are the clinical features of wilson’s disease
kayser-fleisher rings in the peripheral cornea; neuro findings, hepatic dysfuntion
dx of wilsons
decreased serum cerulopasmin(most common screening test); also elevated serum and urine copper; copper deposit in hepatocytes on liver bx
management of wilsons
avoid copper food (nuts, liver, chocolate); chelation therapy; liver transplant in severe cases
menkes kinky hair disease
x-linked recessive; caused by abnormal copper transport; low serum copper
clinical features of menkes kinky hair disease
seizures, pale kinky friable hair, optic nerve atrophy, severe mental retard, early death
dx of menkes kinky hair
typical hair findings and low serum cerulopasmin and copper
definition of short stature
height that is 2 SDs below the mean (below the third percentile)
downward shif in the height percentile in the first 2 years of life
genetic short stature
children who grow how much between 3 yo and puberty generally do not have an endocrinopathy or underlying pathologic disorder
2 inches per year
targeted mid parental height
most kids are within 4 inches of MPH
hypopituitarism
hx of hypoglycemia, prolonged jaundice, cryptochordism, or microphlallus
calculating MPH
5 inches between m and d
normal U/L at birth
1.7
normal U/L at 3 yo
1.3
normal U/L greater than 7 yo
1
short fourth metacarpal
turners syndroe
constitutional short stature
height at least 2 SDs below the mean with a history of delayed puberty in either or oth parents, a delayed bone age and late onset of puberty, and a min growth of 2 inches per year
pathologic short stature
height more than 3 SDs below the mean and growth of less than 2 inches per year
causes of prenatal onset proportionate short stature
environmental exposure, infection, genertic syndromes, chrom disorders
causes of diproportionate short stature (upper body greater than lower body)
rickets, some form of skeletal dysplasia
rickets characteristics
frontal bossing, bow legged, low serum phosphorous
test for GH?
IGF-1; random GH should not be measured, most is released during stage four REM
what radiographic studies help in assessing pathologic short stature?
bone age film and skull radiographs to look at pituitary
bone age < chron age (bones aren’t developing like the rest of you)- what five causes
constitutional short stature, hypothyroidism, hypercortisolism, GH def, chronic disease
bone age = chron age in what 4 causes
familial short stature, IUGR, Turner syndrome, skeletal dysplasia
endocrinopathies that cause short stature
GH def, hypothyroidism, hypercortisolism, turner syndrome
results of GH stimulation test in patients with GH def?
stimulation with L-dopa-Inderal, glucagon, or clonidine gives a poor response
management of GH def
daily subq injections of recombinant GH until 13-14 in girls or 15-16 in boys
most common cause of hypothyroidism
hashimotos (incr TSH, low T4, pos antithyroid peroxidase antibodies)
most common cause of hypercortisolism
iatrogenic as a result of prolonged steroids
sign of hypercortisolism
purple stretch marks, fat bad on neck, decr bone age, weight gain
does GH help in turners
yes
def of precocious puberty in girls
presence of breast development or pubic hair before age 7 or menarches before age 9
def of precocious puberty in boys
presence of testicular changes, penile enlargmetns or pubic or axillary hair before age 9
classic presentation for premature thelarche?
in the first 2 years of life; no tx
classic presentaiton of premature adrenarch
happens after 5 yo; more common in girls; no treatment
Isosexual precocious puberty
aka central precocious puberty; the hypothalamus is activated earier than usual;
most common cause of precious puberty in girls
idiopathic
most common cuase of precocious puberty in boys
organic, all cases need evaluation by MRI of the head
hypothyroidism
precocious puberty, poor growth, and delayed bone age
HPG stim test
pos means central precocious puberty (the HPG axis is turned on!)
