Abstract
Infants with abnormal blood tests for congenital hypothyroidism and inborn error of metabolic disorders are at high risk of being the disease. Additional testing to confirm the screening results of the disease are needed to be performed. In some diseases, many tests may be required to diagnose the disease. Whole genome sequencing is one of the confirmatory tests that can be used in infants with abnormal screening results lead to the precise diagnose and specific treatment.
Methods: children who had confirmed to have abnormal blood results, TSH > 10 mIU/L and/or FT4 < 1 ng/dL from screening of congenital thyroid hormone deficiency and children with confirmation to have abnormal blood results of inherited metabolic disease from newborn screening were invited to participate in the second step of genetic testing in the Genomic Thailand Project for genetic decoding.
Results: There were 59 cases (35 children and 24 parents) in congenital hypothyroidism screening and 57 cases (34 children and 23 mothers) in inherited metabolic disease participating in the project For congenital hypothyroidism, there were 6 children with genetic alterations 2 variants of the thyroid gene (out of 35 cases, 17 percent), 5 cases of the DUOX2 gene (14 percent), and 1 case of TSHR gene (3 percent). For inherited metabolic diseases:
mong 34 children, 20 children were found to have the disease (out of 34 cases, 59 percent)
mostly from primary carnitine deficiency 4 cases (20 percent), 3-Methylcrotonyl-CoA carboxylase deficiency 4 cases (20%)]. Mothers had diseases in 9 cases (out of 34 cases,26%) [Mostly from maternal primary carnitine deficiency 6 cases (18%) and maternal 3-Methylcrotonyl-CoA carboxylase deficiency 3 cases (9%)]. There are 5 cases (from 34 cases,15 percent) being the carrier of inherited metabolic diseases [mostly from citrullinemia type 1, 4 cases (11 percent)].
Conclusion: Whole genome sequencing is another way to confirm, diagnose, and lead to specific treatments for metabolic diseases such as congenital hypothyroidism and inborn error of metabolic disorders.
