Inborn Errors of Metabolism

G6PD Deficiency-Glucose 6 Phospate Dehydrogenase

• Sex linked recessive (X-linked kaya there is more boys than girls)
(bakit boys? Remember that female contains XX genes while male contains X gene. So ibig sabihin if a female had a faulty X gene the other X gene can balance or minimize the effect. So with this principle females are always carriers and males are always affected or they are the ones that manifest the symptoms. Then if the affected male had a female daughter she will be a carrier. To see the complete list of X-linked diseases click on the link: http://philippinenurse.blogspot.com/2008/04/genetics.html)

• Lacks enzyme G6PD results in premature destruction of RBC if cells are exposed to oxidants, ASA, legumes and flava beans

2 forms:

1. Congenital Nonspherocytic Hemolytic anemia- group of congenital hemolytic anemias in which there is no abnormal hemoglobin or spherocytosis and in which there is a defect of glycolysis in the erythrocyte

Characterized by:
Hemolysis, jaundice, splenomegaly and aplastic anemia

2. Drug induced

Precipitating factors:

1. Illness: bacterial and viral infections
2. Anti-pyretic drugs (Aspirin and phenacitin)
3. sulfonamides
4. Anti-malarial drugs (Quinine)
5. Various medications such us Vit. K and Methylene blue
6. Flava beans and Napthalene (eto ung moth balls or naptalina na nilalagay sa cabinet)

Dx Procedure

• Rapid enzymes screening test or electropoetic RBC
• Peripheral blood smear- reveals presence of Heinz bodies (hindi eto ung ketchup, this are RBC’s that appears to have bite off the cytoplasm, that’s why they are sometimes called ‘bite cells’)

Nursing Management

• Instruct to avoid foods such us flava beans, red wine, legumes, blueberries, soya foods, tonic water and other drugs that triggers the attack.

HOMOCYSTINURIA

• elevated excretion of amino acid homocystiene
• It can lead to mental retardation (delays in reaching developmental milestones e.g., crawling, walking, sitting)

REVIEW!!!
Ireview natin ang mga level of Mental retardation
Profound Mental retardation -- IQ 0 to 20 = thinks like an Infant. Can’t be trained
Severe Mental retardation --IQ 20-35
Moderate -- IQ 35-50 = can be trained. Mental age is 2-7y/o. Pre-operational stage
Mild -- IQ 50-70 = Metal age is 7-12. Educable and can go to school
Borderline -- IQ 70-90
Normal -- IQ 90-110
(Balik ulit tayo sa Homocystinuria)

• Inability to convert amino acid Methionine
• Autosomal recessive (this means the gene defect is unknowingly passed down from generation to generation. This faulty gene only emerges when two carriers have children together and pass it to their offspring. For each pregnancy of two such carriers, there is a 25% chance that the child will be born with the disease and a 50% chance the child will be a carrier for the gene defect.)

Signs/Symptoms
• Mental retardation
• Downward subluxation of lens (ectopia lentis)
• Slender built
• Pectus excavatum (meron din nito ang may Down syndrome, the sternum appears sunken and the chest concaves.)
• Abnormal thinning and weakness of the bone (osteoporosis and kyphoscoliosis)
• Degeneration of the aorta

Labtest:
Bacterial inhibition assay for methionine - Normal is 1mg

Congenital Adrenal Hyperplasia

- A condition where the adrenal does not produce enough cosrtisol and aldosterone but there is an excessive production of androgens.
- This is also autosomal recessive

REVIEW!!!
Hormones of the Adrenal Cortex
Ang ating code; SSS
Salt- Mineralocorticoids (mainly aldosterone- responsible for Na reabsorption and K excretion)
Sugar-Glucocorticoids (mainly cortisol, responsible for glycolisis and gluconeogenesis)
Sex- Sex hormones
Oversecretion- Cushing’s syndrome
Undersecretion- Addison’s disease

Assessment:
In female
• Large clitoris, closed labial folds
• Early appearance of pubic hair
• Deep masculine voice
• No breast development and menstruation
• Excessive hair in face
• (in short nagiging lalaki ung babae)

In male:
at birth- normal
6 months signs of sexual precocity
3-4 – have pubic hair and enlarged penis, scrotum and prostate but testes is not descended
sterility

Labtest:
High 17-hydroxyprogesterone
Low serum Na
High serum K

Treatment:
Corticosteroid
Diet: High sodium, low potassium


PHENYLKETONURIA

(PKU) – deficiency of liver enzymes (PHT)
Phenylalaninehydroxylase Transferase – liver enzyme that converts CHON to amino acid

9 amino acids:
valine isolensine tryptophase
lysine phenylalanine

Thyronine – decrease malanine production
1.) fair complexion
2.) blond hair
3.) blue eyes
Thyroxine – decrease basal metabolism
- accumulation of Phenyl Pyruvic acid
4.) Atopic dermatitis
5.) musty / mousy odor urine
6.) seizure – mental retardation

LabTest
GUTHRIE TEST – specimen – blood
- preparation increase CHON intake
- test if CHON will convert to amino acid

specimen and urine
mixed with pheric chloride, presence of green spots at diaper a sign of PKU

DIET:
Low phenylalanine diet- food contraindicated- meats, chicken, milk, legumes, cheese, peanuts
Give Lofenalac- milk with synthetic protein

GALACTOSEMIA

– deficiency of liver enzyme
- GUPT – Galactose Urovil Phosphatetranferase
- Converts galactose to phosphate tranferace glucose
Galactose – will destroy brain cells if untreated – death within 3 days

Dx:
Beutler test – get blood -done after 1st feeding
presence of glucose in blood – sign of galactosemia
galactose free diet lifetime (4life!)
neutramigen – milk formula

CELIAC DISEASE aka gluten enteropathy

Common gluten food:
Intolerance to food with brow
B- barley
R- rye
O- oat
W- wheat

Pathophysiology:
Gluten – glutamine ( normal absorption) - Gliadin ( toxic to epithelial cells of villi of intestines, effects is malabsorption syndrome)

Malabsorption
- Fats = steatorrhea
- malnutrition = edema and
- decrease in vitamin D = decrease in calcium = osteomalicia
- decrease in vitamin K = inadequate blood coagulation = bleeding
- decrease in iron folic acid = anemia


Early Sx:
1. diarrhea – failure to gain wt ff diarrheal episodes
2. constipation
3. vomiting

Late Sx:
abd pain – protruberant abd even if with muscle wasting
steatorrhea

Celiac Crisis- exaggerated vomiting with bowel inflammation

Dx:
lab studies – stool analysis
serum antiglyadin – confirmatory of disease

Mgt:
gluten free diet – lifetime
all BROW – not allowed
rice & corn - OK!
vitamin supplements
mineral supplements
steroids