Autism Spectrum Disorder: Diagnosis

Introduction

In the past 50 years, autism spectrum disorder (ASD) has gone from a hardly defined, rare disorder of childhood onset to a well-publicized and researched lifelong condition, recognized as fairly common and very heterogeneous. The neurodevelopmental and neurobehavioral condition known as an autism spectrum disorder (ASD) is characterized by disrupted emotional processing, repetitive and limited patterns of behavior, activity, or interest, and impaired social communication. Many (but not all) people with ASD need support of some type throughout their whole lives.

Early diagnosis

Doctors in pediatrics, psychiatry, or psychology can diagnose ASD; ideally, a team of experts from different fields should be involved. Other standardized diagnostic instruments are available including the Screening Tool for Autism in Toddlers and Young Children and the more heavily researched Autism Diagnostic Observation Schedule (ADOS;16 a 45-min observation done by a skilled professional). The use of reliable and valid scales is considered very important for the identification and diagnosis of ASD.

Diagnosis in children

About medical issues that exist before an ASD diagnosis, or during the pre-diagnosis phase, very little is known. Some studies that focus on the pre-diagnosis period rely on parent recollections of child histories gathered after an ASD diagnosis, and these reports may be biassed by recall.50% of parents report features of autism in their children by 2 years of age and 93% indicate recognition of symptoms by age 3.

A significant diagnostic issue for young children that has been frequently acknowledged but infrequently addressed is normal patterns of development up to 18–30 months followed by marked regression. Within a short time, children may lose most to all of their speech, decrease socialization activities, and develop “autistic-like” behaviors such as lack of eye contact, fixation on objects, and ritualistic behaviors.

ASD in adulthood

Estimates vary, but 10–33% of adults with ASD mostly use more simple phrases and have verbal and non-verbal IQs in the range of intellectual disability, requiring very substantial support. Most adults with ASD are able to speak, read, drive, complete their education, and live in the neighborhood. For the majority of persons with ASD, the situation has improved and will continue to do so, which should reassure carers.

Environmental risk factors

Many risk factors for ASD have been suggested. Prenatal, perinatal, maternal dietary, and lifestyle factors have all been discussed in a number of systematic reviews and meta-analyses.

ASD and pediatric conditions

ASD is strongly linked to many coexisting conditions, including those that are physical, mental, neurodevelopmental, and functional. Despite not meeting the diagnostic criteria, these conditions can still have a significant, frequently detrimental impact on a child’s or young person’s well-being and that of their family, necessitating the modification of intervention strategies. Other neurodevelopmental abnormalities are among the coexisting conditions, albeit their prevalence varies depending on the community under study.

Genetic disorders such as Down syndrome, Neurofibromatosis Type I, Fragile X syndrome, and Duchenne Muscular Dystrophy are more common in children with ASD.

Genetics

Enrichment studies have shown that genes linked to ASD contribute to significant problems such as neural activity, brain development, transcription regulation, and signaling regulation when looking at the general genetic structure in ASD.

74–93% of ASD risk is heritable, according to a meta-analysis published in 201675; however, non-genetic variables have a significant role as well. Sibling studies show that 7–20% of succeeding offspring have an ASD.

The study involved 100 healthy participants and 200 individuals with ASD between the ages of 3 and 9. Peripheral blood samples taken from volunteers were used to perform Genomic DNA isolation.

The RFLP approach was used for genotyping, and PCR tailored to certain variations was used. With the SPSS v25.0 program that data was analysed. The study’s findings showed that the proportion of people with homozygous genotypes was much higher in the patient group than in the control group and that having a homozygous genotype raised the risk of developing the condition by about 1.8 times.

Neurobiology

In neurobiology, ASD is no longer considered to be a focused defect in a particular system or region of the brain, but rather a disease brought on by a general reconfiguration of the brain that starts early in the developmental stage. A pattern of overgrowth of brain volume in infancy and early childhood, as seen by changes in brain volume on neuroimaging, is one of the most widely repeated discoveries.

Conclusions

Autism spectrum disorders (ASDs) are multifactorial and involve inheritable and environmental factors. Diagnosis of ASD is important in earlier stages of development for better life of individuals, being provided with all the necessities consequently.

~Adrija Ghosh, KRSH Welfare Foundation