November 22 2020 at 01:17 AM by Admin
Angelman syndrome is a type of congenital neuro-genetic disorder that is present in the child from birth. It causes developmental delay and intellectual disability. British pediatrician, Dr. Harry Angelman, was the first to describe the syndrome in 1965. Individuals born with Angelman syndrome have no family history of the disorder and may occur in people of all ethnic backgrounds.
Cause of Angelman syndrome
Angelman syndrome is caused by a mutation, either deletion or inactivation in the maternal allele of the UBE3A gene present on chromosome 15. Normal people inherit one copy of the UBE3A gene from each parent, however it differs in the pattern of methylation (imprinting). There are various reasons for the maternal UBE3A allele not being expressed. The most common reason is the deletion of about 4 Mb in the maternal chromosome region (15q11-15q13) causing an absence of UBE3A expression. The other cause is the mutation in the gene. A novel mutation (cDNA1199 C> A (p.P400H)) in exon 9 of the gene has been identified. In rare cases the disease occurs due to uniparental disomy, in which the patient inherits two copies of chromosome 15 from his or her father instead of one copy from each parent. It can also be caused by a chromosomal rearrangement (translocation). The genetic changes occur as a random during the formation of eggs and sperm, or in early embryonic development.
Symptoms of Angelman syndrome
Harry Angelman described the syndrome as children having "flat heads, jerky movements, protruding tongues, and bouts of laughter". The various symptoms include mental retardation, short attention span, abnormal behavior, developmental delay, microcephaly, feeding problems during infancy, hyperactive tendon reflexes, unstable jerky puppet-like gait, hand flapping, diminished speech and laughter, motor development delay, unusually happy demeanor, blond hair, crossed eyes, decreased eye pigmentation, large jaws, tongue protrusion and widely spaced teeth, excessive chewing/mouthing behaviors, akinetic seizures, arms held up and flexed at wrists and elbows, reduced muscle toning, hyperreflexia, abnormal spinal curvature, sleep disturbance, sensitive to heat and cerebral atrophy.
Treatment for Angelman syndrome
Till date there is no exact and fruitful treatment for Angelman syndrome. Patients must be continually monitored and treated for symptoms throughout their lives. Epilepsy or multiple varieties of seizures has to be controlled by anticonvulsant medications. Many individuals sleep for a maximum of 5 hours at any one time. As the patients have less sleep, use of melatonin can be very helpful to induce sleep. Mild laxatives are also used frequently to encourage regular bowel movements and treat constipation. Speech therapist can help individuals to develop verbal ability and communication ability with people. Physical therapies like regular exercises encourage joint mobility and prevent stiffening of the joints, improving walking. Occupational therapy can help the child develop everyday living skills.
People with Angelman syndrome generally have good health. Sometimes they are known as 'angels' because of their youthful, happy appearance. Angelman syndrome is not a degenerative syndrome. If diagnosed early and managed properly they can be expected to live a normal life span.