My father, Jan Stern, who has died aged 98, was a biochemist who, with his great friend and colleague Len Crome, wrote The Pathology of Mental Retardation (1967), an important book in its field. Jan was also part of the team at the Fountain hospital in Tooting, south London, whose work contributed to the development of the heel prick test carried out on all newborn babies to screen for nine rare but serious health conditions.
Born in a country that no longer exists (Czechoslovakia), to parents who had grown up in an empire – the Austro-Hungarian one – which was to fall, Jan was one of twin boys born to Immanuel Stern, a lawyer, and Helena (nee Schultes). They lived in Brno, Moravia (now part of the Czech Republic), and had a bilingual (German/Czech) existence. Jan attended the local grammar school, and would perhaps have gone on to university in Vienna, like his father, had history not taken the turn that it did.
In 1938 the family, including Jan’s younger brother, Fred – his twin brother, Franz, had died aged six – left Czechoslovakia shortly before the Nazi occupation, travelling via Paris to London.
English was the fourth (modern) language Jan learned, but he managed to get into the University of Leeds to read chemistry, then completed a PhD there in biochemistry. His parents returned to Czechoslovakia after the war but Jan and Fred remained in the UK.
In the 1950s Jan joined the Fountain hospital as a clinical biochemist in the pathology department. His specialism was infant diseases that have a biochemical basis, and he worked on detecting Phenylketonuria (PKU), one of the conditions looked for in the newborn heel prick test. It was also at the Fountain that he met Diana Slomson, a child psychologist, and they married in 1960, eventually settling in Sutton in Surrey.
From the 60s Jan was chief biochemist in the pathology department at Queen Mary’s hospital for children, in Carshalton Beeches in south London, where he stayed until retirement in 1992. He was a fellow of the Royal College of Pathologists, a member of the Royal Society of Medicine and a visiting lecturer at the University of Surrey.
He had a long, productive and happy life. His goal for 2020 was to live long enough to see President Trump defeated, and in this aim he was successful. Jan became a Brit but was for ever continental and a true European. He was, however, saddened by the return of language and attitudes he thought he had left behind him in the 30s.
Fred died in 1977 and Diana died in 2014. Jan is survived by his sons, Simon and me, and four granddaughters, Charlotte, Jenni, Josie and Rosa.
