The problem with many of the non-invasive tests for antenatal diagnosis of Down’s syndrome is their low specificity. Now a simple ultrasonographic marker of Down’s syndrome has been reported. Two thirds of babies with Down’s syndrome have been detected to have an absent nasal bone in the first and second trimester. In contrast only 1% of normal fetuses have an absent nasal bone. However, this figure is as high as 8% in people of African descent. Values for other ethnic groups still need to be worked out. This marker can be picked up as early as 11-14 weeks or in the usual ultrasound examination at 15-22 weeks. Along with other markers like nuchal skin fold thickness and the triple test, this test may reduce the need for amniocentesis. (Nature news service 20 December 2002; Cicero, S., et al. Nasal bone hypoplasia in trisomy 21 at 15-22 weeks' gestation. Ultrasound in Obstetrics and Gynecology, Published online, doi:10.1002/uog.19, 2002).

Should pediatrician's use nimesulide? That is the burning question today. In 1999, 2 children died of suspected Reye’s syndrome in Portugal after using nimesulide. Since then it has been banned in children in most places round the world. 3M Riker was the American company which originally discovered this molecule. For undisclosed reasons, it was never launced in USA. It was sold to Helsinn, which licensed it to Boehringer for sale in Italy. Most countries who allowed it’s use, banned it in children. It came back into the limelight when liver damage was reported in adults in Finland. However, it continues to be marketed with impunity in India for all ages, with freely available drops and suspensions. A public interest litigation has now been filed in the Delhi High Court by the Social Jurist legal group against the availability of nimesulide and other banned drugs in December 2002 (The Times of India 20 December 2002, eBMJ 11 Jan 2003).

Egged on by protests from animal right activists who strongly objected to the production of antisnake venom from horse serum, scientists from the Vittal Malya Scientific Research Foundation, Bangalore have come up with a novel alternative. They injected chickens with sub lethal doses of snake venom. The antibodies produced have been seen to concentrate in the chick eggs. The antibodies which were obtained earlier from 1 litre of horse blood are now available in 50 eggs. The risk of serum sickness due to horse proteins will also go down. Every problem is an opportunity in disguise (The Times of India, 6 January 2003).

Population geneticists after complicated genetic analysis of various ethnic groups are saying what our professors used to say in medical college. A detailed history might be as good as expensive tests. Rosenberg, et al. from the University of South California compared 1000 genetic markers in various population groups from round the world. They found that many features including drug and disease susceptibility and vaccine response was highly congruent in a few broad groups-people from Sub-saharan Africa, Eurasia, South East Asia, the Americas, Oceania. "The correlation between self reported ethnicity and genetic clustering was so high that for everyday medicine intrusive genetic testing would probably not be required." They have also reported some new discoveries; e.g., the Kalash people of North Pakistan seem to be more similar to Europeans than the south east Asians as earlier thought (Science, 298, 2381- 2385, 2002)

Gouri Rao Passi,
Department of Pediatrics,
Choithram Hospital & Research Center,
Indore 452001.
Email: [email protected]