SELECTED STUDIES

By Hajer Al-Hosani, Mohamed Salah EL-Din, H. Osman, T. Mustafa, H.M. Farrag, D. Saade

Ministry of health has established in 1994 an advisory committee for neonatal screening which has a supervisory role over the program as a whole .

The program started by screening for :

- Phenylketonuria in January 1995.
- Congenital hypothyroidism in January 1998.
- Sickle cell disease in January 2002& March 2005.
- Congenital Adrenal Hyperplasia in January 2005 .

Objectives

· Treatment of Phenylketonuria or Congenital Hypothyroidism will be initiated by the age of 21 days to prevent mental retardation.

· Treatment of Sickle cell disease will be initiated by the age of 2 months to reduce mortality and morbidity and to improve outcome.

· Detection of infants with hemoglobin traits affords an opportunity for genetic counseling and for the identification of couples at risk for having subsequent children born with a disease.

· Treatment of Congenital Adrenal Hyperplasia will be initiated by the age of 14 days to prevent serious salt loss crises and earlier correct gender assignment in virilized girls.

Protocol

The following protocol covers all stages of the screening program:

a. Invitation for screening
b. Specimen collection
c. Laboratory analysis
d. Follow up of positive cases
e. Management of affected infants
f. Systematic evaluation of all phases of the program

a- Invitation for screening:

Every baby born in a hospital setting , where 99% of mothers usually deliver , will be given a form for neonatal screening and an information leaflet and the mother will be told where to take her baby for screening (usually MCH center of that district) .

b- Specimen collection:

•-The baby will attend the designated center on the third day (³72 hours).
•-Blood is collected by a heel prick onto the filter paper by technicians or trained nurses.
•-The district MCH coordinator is responsible for contacting defaulters.

c- Laboratory analysis :

TSH , Phenylalanine and 17α- OH Progesterone are assayed by Delfia Fluorometric method .

The Same filter papers will be tested for sickle cell disease by High Performance Liquid Chromatography (HPLC) variant System .

d- Follow up:

Any positive screen is notified immediately to the central department of MCH by the Lab .The district MCH coordinator will be informed and will contact the parents.

For a baby screening positive for PKU , Congenital Hypothyroidism & Congenital Adrenal Hyperplasia blood will be taken to confirm diagnosis.

For a baby screening positive for Sickle Cell Disease or Trait blood will be taken from the baby and other family members before the age of 2months for disease and 4 months for trait to confirm diagnosis and genetic counseling .

e- Management:

The affected infants will be assessed by the designated consultant and management should be initiated at the earliest opportunity regardless of whether investigations have been completed or not.

f- Systematic Evaluation:

Systematic outcome evaluation of all phases (Pre-analytical, analytical and post-analytical) and all data of the program by the central MCH Department.

Evaluation

A- Coverage (% uptake).

B- Timeliness of the screening program indicators (age of sampling, time of delivery of the specimen to Lab, time taken by the lab to produce the result , age of recall and age of treatment initiation) .

C- Unsatisfactory Specimen Quality.

D- Indicators for evaluation of validity of test (recall rate,the apparent sensitivity,specificity and positive predictive values).

E- Follow up results

Compared to the international standards

Action taken to increase the uptake:

•-Routine checking of specimen against birth notification register.
•-Raising community awareness.
•-Design system for recall for defaulters.
•-Health education e.g. Perinatal joined with breast feeding program.
•-Screening status is recorded on the well baby flow sheets along with immunization.

C- Unsatisfactory Specimen Quality:

Our results:

In 1995 , 1996 and 1997 : >3% of specimen.

In 1998 – 2002 :<3% of specimen.

In 2003 -2005 : 0.1%of specimen.

Target:
< 3% of specimen.

Thyroid scan was performed on 163 confirmed cases.

The gland was:

- ectopic in 76 (46.6%).
- eutopic with increased uptake ,which suggests dyshormonogenesis in 53 (32.5%).
- athyrotic in 34 cases (20.9%).

Follow up results :

Since the implementation of the program (from January 1995 until DEC 2005) : 385,1435 infants were screened with relative incidence of :

- 1:1963 for congenital hypothyroidism (188 cases were prevented from mental retardation).

- 1:14,812 for classical PKU (26 cases were prevented from mental retardation).

- 0.06% for sickle cell disease (83 cases) and 0.9% for sickle cell trait (n=1154) in our program .

* Pilot study of congenital adrenal hyperplasia : 4 cases (3males & 1 female) with the classic type .

Future Plans

* Increase the uptake rate to reach 99 % by the year 2010 .

*Additional of others tests to the program:

-- Maple syrup urine Disease (MSUD)
- Galactosemia
-

Newborn screening no longer refers only to the screening tests themselves, but includes all of the elements essential for every neonate to have access to a screening system that is optimal in terms of quality and performance .

It should be possible to achieve almost 100% uptake, detect nearly all affected babies , start early treatment and all the babies will have normal physical and mental development .

For the screening programme to be successful meticulous care is needed in following the procedures by all involved

Dr. Mohamed Salah EL-Din is a consultant Medical Geneticist at the National Screening Program for Woman and Child Health, Central Department of Maternal and Child Health, Ministry of Health, UAE.