Children, Adolescents, and Young Adults with Borderline Intellectual Functioning: Etiological, Neurophysiological, and Mri Findings in a Cohort of 651 Patients

Round 1

Reviewer 1 Report

The authors describe in a clear way a retrospective chart review exploring the etiology, use, and yield of the etiological investigations in 651 children with borderline intellectual functioning (BIF). A primary etiological diagnosis was found in 37,6%, in the same range as found in children with developmental retardation. 

This study confirms the importance of etiological investigations in persons with BIF.

In the presentation of the results I miss the comments on the meaning of every finding mentioned in the Tables. 

Some findings are primary etiological, some findings contributing, some findings incidental unexpected, some findings unknown, and maybe more...

I think the authors should mention the meaning of every finding in the Tables.

 

   

Author Response

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Reviewer 2 Report

This is high-quality  retrospective chart review study explored the etiology, use, and yield of the etiological investigations of 651 children and adolescents diagnosed with borderline intellectual functioning (BIF). The authors wrote the research method and provided all the necessary results. This research can definitely raise awareness about the possible causes of BIF among medical professionals.

However, it could be interesting if authors can explain in more details the importance of fragile X testing, how often this test is used, how familiar doctors are with fragile X, etc. According to my opinion, this is important because the fragile X syndrome is the most common monogenetic cause of intellectual disability, and such paragraph in Discussion can improve the article. In addition, only 182 individuals were tested on Fragile X? Can authors include inclusion and exclusion criteria for testing on FX?

In addition, they referred that 89 (13.7%) individuals had autistic features. Please, can authors define which autistic features were presented in this cohort? And how many individuals have been diagnosed with autism? 

Author Response

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Reviewer 3 Report

This is an interesting retrospective study assessing etiology in 651 children and adolescents with borderline intellectual function- 18 ing (BIF). The Authors found an etiological cause in 37.6% of cases, mostly due to pre- or perinatal conditions, genetic abnormalities,theratogenesis, cerebral malformations, and neurological diseases. The best etiologic yield leading to diagnosis resulted exome sequencing, specific gene panel, microarray, electroneuromyography, and brain MRI. No statistically significant difference  in the proportion of abnormal findings between the BIF and intellectual disability groups was found. The Authors recommend a targeted etiological work-up driven by careful history and neurological examination, and warrant national guidelines taking in count the severity of the developmental delay.

Although the paper has several limitations, it has the strength to assess the diagnostic work-up and yielding in a special population of patients, i.e. those with BIF, that have not been studied in detail in literature.

Data are clearly reported and discussed. English style is rather adequate.

As a minor point, in the Table 5, the term "irritative", "finding", "epileptic disorder" or "non-specific" are misleading and usually not used in epileptological or EEG literature. So, I would suggest to change this term. So, "focal finding without epileptic disorder" should be "focal epileptiform abnormalities without epilepsy"; focal irritative findings related to focal epilepsy" should be "focal epileptiform abnormalities related to focal epilepsy"; "non-specific bilateral spike-slow waves without epileptic disorder"  should be "bilateral spike-slow waves without epilepsy"; "bilateral irritative findings related to generalized epilepsy" should be "bilateral epileptiform abnormalities related to generalized epilepsy"; "focal irritative findings related to prenatal/perinatal incident" should be "focal epileptiform abnormalities related to prenatal/perinatal incident". 

Author Response

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