Researchers at Chungnam National University has found a new gene that causes Armfield syndrome, a disorder accompanied by developmental and intellectual disabilities, and identified the mechanism of action at the molecular level.
|Chungnam National University Professor Kim Chul-hee and his research team have found a new gene that causes Armfield syndrome and identified the mechanism of action at the molecular level. (CNU)|
Armfield syndrome, first reported in 1999, is also a major cause of autism. The disease is an X-chromosome-related intellectual disorder that affects only men.
The team, led by Professor Kim Cheol-hee, found FAM50A as a candidate gene for Armfield syndrome through a four-generation family tree analysis, gene mapping, and patient genome big data in 2015. Director Charles Schwartz at the Greenwood Genetic Center in the U.S. also participated in the study.
To verify their results, the team conducted a zebrafish model animal experiment using genetic scissors technology and RNA transcript and protein big data analysis. The researchers then identified the action principle of FAM50A at the molecular level, and finally confirmed that the gene as a causative agent of intellectual disability.
|Pedigrees of the five families reported in this study are shown, with FAM50A genotype given for each available individual. Photographs of available affected males are provided for each pedigree. For family K8100, photographs are provided for the two affected males in generation IV at ages 8 and 4 years, when the family was originally published4; new photos from the last clinical assessment (December 2017) are shown (28 and 24 years). Ratios under females II-2, III-2, III-3, III-5, and IV-3 represent X-inactivation data. Females II-3 and II-7 were uninformative (ui) at the AR locus. Circles, females; squares, males; unfilled shapes, unaffected; black filled shapes, affected; unshaded circle with black dot, carrier female as determined by FAM50A analysis or by pedigree structure; diagonal line, deceased. Male K8100-III-6 had macrocephaly, seizure disorder, bilateral ventricular enlargement, and atrophy of the left hemisphere on a pneumoencephalogram; he was unavailable for FAM50A genotyping.|
The finding is the outcome of 20 years of research efforts from patient reporting to the discovery and verification of the causative gene,” the team said. “Thanks to advances in patient genome big data analysis technology and cutting-edge genetic scissors technology, we could present a breakthrough in the field of developmental and intellectual disability research, whose causes were unknown in the past.”
Professor Kim said, “The intellectual disorder and epileptic gene discovered in 2015 laid the cornerstone for the global patient foundation establishment in 2018, and it can be used as a molecular diagnostic biomarker.”
This study can also be used as a biomarker for early molecular diagnosis in the short term, and as a source technology for developing therapeutics through disease modeling in the mid- to long term, he added.
The journal Nature Communications published the study in its July edition.