Down syndrome in one of non-identical Nigerian twins: a case report

Down syndrome (DS) or Trisomy 21 is the most frequent and best known Trisomy in humans. Mothers under 25 years of age are known to have the average risk of a DS pregnancy of 1:1600, rising to 1:350 at 35 and 1:40 at age 43. Twining in DS occurs at a rate of 1.2% of pregnancies with only 1/6th of both of the pairs having Trisomy 21.

A 4-week-old male, second twin, was admitted in the University of Port Harcourt Teaching Hospital (UPTH) due to fast breathing from birth, cough and poor weight gain. He was very pale, (haematocrit 18%), dyspnoeic and had mongoloid features. There were coarse crepitations in lung fields, a systolic murmur and an enlarged liver The diagnoses were Down syndrome, bronchopneumonia and congenital heart disease with failure. The mother was aged 22 years and the twin sister was normal.

He was promptly treated with oxygen, diuretics, and antibiotics but died within three hours of admission before blood transfusion could be offered.

Down syndrome in twin pregnancy is very rare and, to our knowledge none has been reported in Nigeria. That this was a product of first pregnancy in a lady as young as 22 years makes an interesting reading.