Newborn Screening Flashcards
Newborn Screening
Congenital Hypothyroidism Congenital Adrenal Hyperplasia Galactosemia Phenylketonuria Glucose 6 Phosphate Dehydrogenase Deficiency MSUD
On what day of life is NBS done
24-48 hrs
<24 hrs repeat at 2 weeks old
PRETERM - 5-7 days
can be done until 1 month (for sick babies)
RA 9288
Newborn Screening Test
covers 28 diseases
CONGENITAL HYPOTHYROIDISM
macroglossia
mental and somatic retardation
delayed tooth eruption
prolonged physiologic jaundice > 14 days
Expanded Newborn Screening
6-28 diseases
Hemoglobinopathies Disorder of AA and organic acid metabolism FA oxidation Carbohydrate metabolism Biotin metabolism Cystic fibrosis
AR disorders of cortisol biosynthesis
Deficiency in cortisol – INCREASED corticotropin (ACTH) – adrenocortical hyperplasia and overproduction of intermediate metabolites
Congenital Adrenal Hyperplasia
PATHWAY:
mineralocorticoid deficiency or excess
incomplete virilization or precocious puberty in males
virilization or sexual infantilism in females
Enzyme deficient in CAH (90%)
21 hydroxylase enzyme
Enzyme being tested in CAH
17 hydroxyprogesterone (elevated)
Lab findings in CAH
HYPOnatremia
HYPERkalemia
HYPOglycemia
17 alpha hydroxylase deficiency
XY: atypical genitalia, undescended testes
XX: lacks secondary sexual devt
DELAYED PUBERTY
INCREASED mineralocorticoid DECREASED cortisol DECREASED sex hormone HYPOkalemia HPN
decreased androstenedione
21 hydroxylase deficiency
MC
present in infant (salt wasting) or childhood (precocious puberty)
XX:virilization
DECREASED mineralocorticoid DECREASED cortisol INCREASED sex hormone HYPERkalemia DECREASED BP
increased renin
increased 17 hydroxyprogesterone
11 B hydroxylase deficiency
Presents in infancy (severe HPN) or childhood (precocious puberty)
XX: virilization
DECREASED aldosterone INCREASED 11 DEOXYCORTICOSTERONE (INCREASED BP) DECREASED cortisol INCREASED sex hormone HYPOkalemia HPN
decreased renin
Treatment for CAH
Glucocorticoid replacement - HYDROCORTISONE
Mineralocorticoid replacement - FLUDROCORTISONE
Surgical management
Prenatal management - DEXAMETHASONE (for females only)
Episodic or chronic hemolytic anemia
Symptoms develop 1-2 days after exposure to a substance with oxidant properties - sulfonamides, nalidixic acid, nitrofurantoin, chloramphenicol, antimalarials, vitamin K analogs, ASA, benzene, naphthalene
G6PD deficiency
3 distinct enzyme deficiencies in Galactosemia
Galactose 1 phosphate uridyltransferase deficiency (GALT) - classic form
Galactokinase deficiency (GALK)
Galactokinase 4 epimerase deficiency (GALE)
Galactosemia
Accumulation of galactose 1 phosphate and uridine diphosphate galactose – KIDNEY, LIVER, BRAIN
feeding intolerance, vomiting, jaundice, convulsions, lethargy, hypotonia, mental retardation
at INCREASED RISK for E. COLI NEONATAL SEPSIS
Presents with CATARACTS
Galactokinase Deficiency (GALK)
Treatment for Galactosemia
Lactose free milk
Long term sequelae of galactosemia
ovarian failure
devt delay
learning disability
Enzyme deficient in phenylketonuria
Phenylalanine hydroxylase
deficiency – HYPERPHENYALANINEMIA
Effects of excessive phenylalanine
excess phenyalanine – transaminated to PHENYLPYRUVIC ACID or decarboxylated to PHENYLETHYLAMINE – disrupts normal metabolism – BRAIN DAMAGE
MC manifestation of phenylketonuria (without treatment)
DEVELOPMENTAL DELAY
Phenylketonuria
Severe vomiting hypertonic hyperactive DTRs seizures older hyperactive with purposeless movements rhythmic rocking and athetosis
UNPLEASANT MUSTY ODOR
Kidney, Liver, Brain
Galactosemia
Musty odor, neurologic manifestations, gradual
Phenylketonuria
Maple syrup odor, neurologic manifestation, earlier in onset
MSUD
Chronic or acute hemolytic anemia
Triggered by oxidative stress
G6PD
Normal at birth Ambiguous genitalia Vomiting Sexual and somatic precocity Hyponatremia, Hyperkalemia, Hypoglycemia
CAH (21 hydroxylase deficiency)
Delayed physical, mental and sexual devt
Macroglossia
GDD
Congenital hypothyroidism
Accumulation of branched chain keto acid toxic to the BRAIN - leucine, isoleucine, valine
defective activity of the enzyme branched chain alpha keto acid dehydrogenase complex
Maple Syrup Urine Disease (MSUD)
