Angelman's syndrome.

Angelman's syndromeAngelman's syndrome is one of the causes of severe mental handicap that is associated with a characteristic facial and behavioural phenotype.It was first described by Harry Angelman in 19651 and was reported only infrequently in the literature up until 1987 when a proportion of patients with the syndrome were noted to have a small deletion of the long arm of chromosome 15 at 15qll-13.2 3 Since then interest in Angelman's syndrome has grown, leading to an increased frequency of diagnosis and greater awareness of the clinical features of this condition.4Clinical history The infant with Angelman's syndrome is usually born after a normal pregnancy and the birth weight is approximately 200 g less than normal siblings.In the neonatal period feeding problems are common, with difficulty in establishing breast feeding, gastro-oesophageal reflux, and poor weight gain even though the infant appears to suckle for long periods.The babies are often tremulous on handling and frequent jerky movements become apparent during the first months of life.Smiling begins at the normal time but there is a delay in motor milestones with inability to sit unsupported until around 12 months.There is appreciable truncal hypotonia but in contrast the limbs are usually stiff.Crawling is commonly in the 'commando' style and inde- pendent walking is generally achieved at around 3 to 4 years, although some children walk as early as 2 years.A minority do not become ambulant, and these children tend to have the greatest degree of limb spasticity or additional problems such as scoliosis or cerebral palsy.The gait in Angelman's syndrome is characteristically ataxic with a wide base and stiff legs.The arms are upheld and flexed at the elbow, a posture which led to the condition being known as 'happy puppet syndrome'.5This name was not popular with parents and other carers and is no longer in common use.