Incidence of neonatal hyperphenylalaninemia in fars province, South iran.
OBJECTIVE
Phenylalanine hydroxylase or its cofactor, tetrahydrobiopterin (BH(4)), deficiency causes accumulation of phenylalanine in body fluids and central nervous system. Considering the fact that hyperphenylalaninemia is a preventable cause of mental retardation in infants, the objective of this study was to determine the incidence of congenital hyperphenylalaninemia in Fars province, south of Iran.


METHODS
In a period of one year from November 2007 to November 2008 blood samples were withdrawn from all newborns born in Fars province for measurement of serum phenylalanine. The samples with a serum level of≥ 2 mg/dl were referred to pediatric endocrine clinic for confirmation and determination of the type of hyperphenylalaninemia by quantitive serum phenylalanine measurements by using High-Pressure liquid chromatography (HPLC) method.


RESULTS
Nine out of 76966 newborns had a serum phenylalanine level≥2mg/dl, of which 8 cases were confirmed by HPLC. The incidence of the disease was 1:10000. The incidence of mild hyperphenylalaninemia and phenylketonuria (PKU) among the patients was 62.5% and 37.5% respectively and the incidence of BH(4) deficiency was 1/76966.


CONCLUSIONS
These findings indicate a high incidence of hyperphenylalaninemia, in the newborns from Fars province. The high incidence makes a comprehensive screening program for management of the disease necessary.
Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, IR Iran.
Hamdollah
H
Karamifar
Mahtab
M
Ordoei
Zohreh
Z
Karamizadeh
Gholam Hossein
GH
Amirhakimi