Posted On May 07, 2020
HOD & Consultant - Medical Genetics
Manipal Hospitals - Old Airport Road - Bengaluru
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Autism spectrum disorder (ASD) is a neurological and developmental disorder that affects communication and behaviour. It is known to cause a triad of impairment in imagination, language and social interaction. ASD has a ‘spectrum’ word in it as there is an array of conditions and symptoms people experience. It includes various conditions that are diagnosed separately such as autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS) and Asperger syndrome.
According to the Centre for Disease Control and Prevention, US (CDC~2016), 1 in 54 individuals are affected by ASD. It is more than 4 times more common among boys than among girls.
The exact cause of ASD is not known. The majority are idiopathic or due to acquired brain injury. Genetic factors play a major part in ASD and 15-40% will have an identifiable genetic cause. It may be caused by several genes acting together with environmental factors, some are secondary –syndromic. Children whose brother or sister have ASD are at a higher risk of also having ASD.
Presentation of symptoms differs between children with ASD; some are perceived by parents as different during infancy, others present with delayed speech development and a proportion regress and lose skills after the ﬁrst year of life.
In infancy-absence of the social smile by 3 months, more interested in objects than faces, no response to name, inability to follow pointing hand and struggling to imitate actions, No vocalization by 6 months and babbling by 1year.
Commonly seen signs are:
Restricted and repetitive behaviour
Unusual attachments to objects
Stereotypies include hand flapping, finger movements, rocking or twirling
Hyperactivity, delayed motor skills with poor coordination
Social skills deficits- prefer being alone, do not make eye contact
Learning difficulty, around 75% of children will have an intellectual disability
Diagnosing ASD can be difficult, as there is no direct test. It takes the comprehensive holistic evaluation of an individual to place them in the spectrum. This involves developmental screening and comprehensive diagnostic evaluation.
The intervention provided before three years of age has a much greater impact than intervention provided after age five. It will help in:
The child’s overall language development
Improvement in cognitive functions
Gains in the initiation of spontaneous communication
Understanding the genetic diagnosis
Helps identify other underlying health conditions.
Helps provide an understanding of recurrence risk and planning for a future pregnancy.
Current Autism Databases consist of around 1036 reported genes and 2274 reported Copy number variations (CNVs). It is advised to visit the best genetics hospital in Bangalore for early diagnosis. Some of the common genetic conditions and CNVs associated are:
Common CNVs- 1q21.1dup, 7q11.23 dup, 15q11-q13 dup, 16p11.2 del/dup and 22q11.2 del.
Recommended Genetic screening:
Pedigree analysis and clinical evaluation
Chromosomal microarray and Fragile-X testing as a first-tier investigation
MECP2 gene study for females
Targeted gene testing for a suspected specific syndrome
Metabolic testing if clinical indications are seen
Autism is not a medical condition with treatment or a "cure". However, it can be managed and support can be given to the people who need it. Research shows that early intervention can improve a child’s development. However, there is no single best treatment for ASD. Consult with a top genetics doctor in Bangalore to know more about the treatment procedure.
Recurrence risk in a future pregnancy:
If a Genetic cause is identified then accurate recurrence risk and prenatal diagnosis can be offered for future pregnancy. Otherwise, the risk of recurrence is 3-14%.
Head of Department & Consultant, Medical Genetics
Manipal Hospitals Bangalore – Old Airport Road