A recent study published in the journal Genetics in Medicine examined clinical or phenotypic characteristics associated with genetic diagnosis in people suffering from neurodevelopmental disorders (NDDs). NDDs are actually highly heritable and have a lifetime impact on patients. These disorders include intellectual disability, autism spectrum disorders (ASD), and global developmental delays.
Study insights
In the current study, American researchers looked into clinical characteristics of patients with neurodevelopmental illnesses that were linked to genetic diagnosis. Testing for thechromosomal microarrays (CMA), single-gene sequencing, fragile X syndrome, exome sequencing (ES), and mitochondrial deoxyribonucleic acid (DNA), were among the genetic tests available. Those that were selected to participate were split into three groups by the researchers: the ES-negative group, the negative study group, and the pathogenic group or the potentially pathogenic based on the variations.
The researchers looked at the ages at which people walked for the first time, sat for the first time, spoke their first word to their first phrase. But they also looked at the individuals’ medical history, which included head size, language delays, attention-deficit hyperactivity disorder (ADHD), seizures, motor delays, congenital heart diseases, hypotonia, neurological disorders, microcephaly, macrocephaly, and early interventions. Some of the interventions that were received for developmental abnormalities before the age of three were considered early interventions and were included in the research to get more accurate information.
What researchers found is genuinely intriguing.
Individuals who were diagnosed with microcephaly had occipitofrontal circumferences that were only two standard deviations less than the average. In the case of macrocephaly, the occipitofrontal circumference of a person was actually found to be greater than the mean by a couple of standard deviations. 246 of the 316 subjects underwent genetic testing, and 152 of them (or 62% of the total) were found to have an LP/P variation. Furthermore, the remaining 94 people had either a benign VUS variant, no VUS, or neither (this refers to as the negative testing group).
In most cases, the individuals who received positive results from genetic tests were female and had a history of early intervention, hypotonia, motor delays, and congenital heart ailment. A one-month delay in walking age was associated with a five percent to eleven percent increase in the risk of possessing an LP/P variation. As a result, that reflects a strong relationship with early developmental milestones.
Finally, in comparison to the group that did not have ES, linguistic delays were also found to have a significant relationship with the existence of LP/P variations (odds ratio, 3.2).
In the future, large-scale research could be conducted to develop clinically useful decision support tools for the purpose of stratifying individuals with neurodevelopmental disorders (NDDs) for genetic testing. This would definitely improve diagnosis accuracy and accessibility, particularly for populations that are underserved.