Specific and effective treatment is possible for many inborn errors due
to advances in the understanding of their biochemical basis. Early
clinical diagnosis is essential in ensuring that the affected infants
will be benefited by these advances. Some of the modalities of
treatment include regulation of substrate accumulation by restricted
dietary intake (phenylalanine in phenylketonuria), regulation of
endogenous production of substrate (NTBC treatment of hepatorenal
tyrosinemia), acceleration of removal of substrate (dialysis or sodium
benzoate in urea cycle disorders), replacement of products (thyroxine
in inborn errors of thyroid hormone biosynthesis), enzyme replacement
and gene transfer therapy.
Treatment of diseases that occur due to mutation in the protein
affecting the utilization or binding of a vitamin cofactor, with
pharmacological doses of the vitamin, often results in correction of
the metabolic defect and reversal of the signs of the disease.
when treatment options are limited, there are benefits that follow an
early diagnosis. A definitive diagnosis in a sick child avoids further
unnecessary investigations, permits an accurate assessment of
prognosis, and prevents the loss of an opportunity to make the
diagnosis in the case of the death of the child. Furthermore, genetic
advice can be offered to families with the prospect of prenatal
diagnosis for future pregnancies, identification of other affected
family members and carrier detection.