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Pku sCREENING. F.Ahmadbadi Child neurologist ARUMS. Objectives. Epidemiology of PKU in Iran and world Definitions and types Biochemical view Clinical Manifestations Diagnosis Screening Treatment. Epidemiology & Genetic. Prevalence:1/6000-1/10000 Brazil, china,Lativa:1/20000
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PkusCREENING F.Ahmadbadi Child neurologist ARUMS
Objectives • Epidemiology of PKU in Iran and world • Definitions and types • Biochemical view • Clinical Manifestations • Diagnosis • Screening • Treatment
Epidemiology & Genetic • Prevalence:1/6000-1/10000 • Brazil, china,Lativa:1/20000 • AR transmission • F=M • In a study in Shiraz 1/4700 • 2-3% of causes of MR s
Definition: Ph A level more than 6 and Tyrosine low than 5 Types of PKU • Classic • Malignant(2% of cases) • Transient phenylalaninemia
Phenylketonuria Phenylalanine Tyrosine Phenyl ketones PAH THB
BH4 is necessary for: Tryptophan Serotonin Tyrosine Dopamine Hydroxylation
Clinical manifestation • Normal at birth • Severe MR(IQ<30) • Blound appearance • Odor • Microcephalia • Seborroic dermatitis • Dominant maxilla
Diagnosis • Ferric chloride test(urin phenyl ketones) • Guthrie test Screening test • MS/MS • Phenylalanin>6mg/dlit(360 mic M) Diagnostic test • Thyrosin (low) • Phenylalanine hydroxylase gene probe
PhA Level <4mg/dl Report 4≤mg/dl Re check (Filter paper or Serum) HPLC <4mg/dl Report Screening For PKU In 3rd- 5th day of life Under observe 6mo-1 year And then Challenge test Under observe till 1 week & PhA Recheck Diet & Treatment 4-7 mg/dlit 7≤ mg/dlit
False Negative First days of life(1-2) The false-negative rates ranged from 2% to 31% for the first day of life, but decreased to 0.6% to 2% on the second day and to 0.3% by the third day Technical errors Method Humidity Hemodialyse Exchange Transfusion NPO
False PositiveIn certain situations and population conditions, the ratio of false positives to true positives is as high as 32 to 1.8 • Buffy coat in sample • Hemolysis • Prematurity • Liver diseases • Tyrosinemia • Renal diseases • TMP-SMX • Maternal PKU
Treatment • Low phenylalanin Regimen (Phenylalanin2-6mg/dlit) • Treatment must start in first 7-10 days of life. • It must be continued till 10-12 yrs old or even lifelong. • In malignant PKU, Neurotransmitters are needed. • (BH4-Dopamin_serotonine) • Maternal hyperphenylallanenimiaMR-Microcephallia-CHD
Lofenolac • Comida(A,B,C) • Xp-Analog • Xp-Maxamaid • Xp-Maxamum
Some drugs such as Farmentin have aspartame and thus not suitable for PKU cases • Diet drinks (carbonated) have Aspartame.