Face-scan can spot genetic illnesses

Published on Monday 10 September 2007 00:36

SCIENTISTS have developed a computerised face-recognition system that can diagnose autism and other genetically inherited diseases from telltale differences in facial features.

The shape of the face and the size and position of the eyes, the ears, the nose and the lips can point to a wide range of genetic illnesses - from rare disorders of the heart and brain to more common conditions such as autism.

The differences in the features of normal and abnormal children are often so subtle even very experienced medical specialists can often only diagnose them with expensive and time-consuming DNA tests.

But now researchers at London's Great Ormond Street Hospital for Sick Children have developed a computer programme that can analyse and interpret the tiniest variations in face shape and features.

Professor Peter Hammond, a specialist in computational biology at the Institute of Child Health at University College London (UCL), said yesterday it could revolutionise diagnosis and treatment of conditions affecting tens of thousands of people.

"Some conditions are very obvious; for example, you can spot a kid with Down's Syndrome a mile away, but there are over 700 genetic conditions that involve unusual and often very subtle facial characteristics," he said.

"These are sometimes called heart and face syndromes because the development in the embryo of the heart, the face and the brain are closely linked - and that's why if there's something unusual about the face this is often also seen in the brain or the heart. Affected children may have eyes set further apart, ears set lower on the head, a shorter nose, fuller lips, a larger tongue or a mouth narrower than in children of typical development."

Prof Hammond and his colleagues at UCL have developed a programme that can make a three-dimensional copy of a child's face using 25,000 reference points to construct every minor contour. The images are then digitised and compared with a database of thousands of different face shapes to determine whether there is a match with known genetic conditions.

So far the system has been programmed to identify 30 different conditions with an accuracy rate of 90 per cent.

"When our computer identifies a face it should speed up the whole diagnosis process which can be drawn out and expensive - and this should benefit the child and the parents," said Prof Hammond, who will report his findings today to the British Association for the Advancement of Science's conference in York.

"Some of these conditions have a profound effect on the child and the family who want a diagnosis as quickly as possible because they want to know what the risks are to any future children and they want to make sure they get the best.

"For example, a child could have a potentially difficult heart condition which we might otherwise miss. Important medical treatment could be delayed and in situations where an illness leads to unusual behaviour, it's better to start training while the child is still young to avoid certain situations."

The system is already being used as a training aid to help paediatricians recognise some of the more obscure genetic conditions.

THE TELL-TALE SIGNS

Williams syndrome: Affects one in 10-20,000 children, causing learning difficulties and problems with the heart, kidneys, muscles and skeleton. Facial features include a turned-up nose, narrow head, and small jaw.

Fragile X syndrome: The leading cause of inherited mental retardation. It affects around one in 3,600 boys and one in 4-6,000 girls and can be associated with autism. Boys with the syndrome have elongated faces and protruding ears.

Jacobsen syndrome: Affects one in 100,000 children and can cause mild retardation, heart defects, and slow growth. Facial features include wide-spaced eyes, droopy eyelids, low-set ears, a small, receding chin and a thin upper lip.

Cornelia de Lange: Affecting one in 40,000 babies, children have limb abnormalities, remain small for their age and are slow learners. Facial features include thin eyebrows, low-set ears, widely spaced teeth, a short upturned nose and down-turned lips.

Noonan syndrome: A genetic disorder affecting one in 2,500 children it causes webbing of the neck and abnormal chest shapes. Facial features include abnormally shaped ears and widely spaced eyes.

Smith-Magenis syndrome: Affects one in 25,000 causing developmental delays, learning difficulties and behavioural problems. Facial features include a flat, broad head and prominent forehead, heavy brow and up-slanting eyes.