St. Mary’s Hospital’s Genetic Diagnostic Test Center has published the results of a study that confirmed chromosomal microarray analysis is clinically useful in diagnosing congenital genetic diseases.
Chromosomal microarray analysis is a molecular genetic test that mainly targets developmental disorders, idiopathic intellectual disabilities, autism, and congenital anomalies. It is the latest technique that can diagnose genetic diseases that is otherwise undetectable by conventional karyotyping.
In Korea, only a karyotype test, which is a general chromosome test, is performed as a primary test for the target patient.
To confirm the clinical efficacy of the analysis, the team, led by Professors Park Joo-hyun and Sung In-kyung at the hospital, conducted both the chromosomal microarray analysis and karyotype test on 712 participants (617 congenital genetic diseases patients and 95 family members) at five of the St. Mary’s Hospital branches. The branches included Seoul St. Mary’s Hospital, Yeouido St. Mary’s Hospital, Incheon St. Mary’s Hospital, St. Vincent Hospital, and Daejeon St. Mary’s Hospital.
Of the patients, 472, or 77 percent, were younger than five years old, of whom 60.3 percent were male.
As a result, the team found disease-related gene abnormality in 122 patients (19.8 percent) when using the chromosomal microarray analysis, while only detecting 6.2 percent using a karyotype test.
In detail, the team detected in 65 patients had genetic abnormalities, while 57 patients had gene abnormalities thought to be highly related to the disease. Among the remaining 51 patients, the researchers discovered variants of unknown significance.
The researchers also conducted a survey with 39 questions to determine how the results of the chromosomal microarray analysis applied to the diagnosis and treatment of the patients to professors from the pediatrics and rehabilitation medicine department. The professor replied that the chromosomal microarray analysis had influenced other commissioning requests, additional imaging tests, continuous follow-up tests, and drug prescriptions.
Based on the results of the chromosomal microarray test, the hospital could present an optimal treatment direction to 71.4 percent of the patients.
“As a result of this large-scale clinical study, chromosomal microarray analysis showed a higher diagnostic detection rate than the general karyotype test,” said Professor Kim Myung-shin, head of St. Mary’s Hospital’s Genetic Diagnostic Test Center. “If expanded to primary screening, it will be helpful for future genetic diagnosis.”
Annals Laboratory Medicine published the results of the study.