Molecular newborn screening of four genetic diseases in Guizhou Province of South China

• MALDI-TOF MS genotyping is a high throughput method for mutations screening.
• MALDI-TOF MS-based newborn screening program for four genetic diseases was established.
• The carrier frequencies of four genetic diseases in Guizhou Province were elucidated initially.

Genetic disorders have been a major concern for public health in China, especially in the rural regions. However, there is little information available about prevalence of many common single-gene disorders in Guizhou Province in the south western part of China. In the present study, we performed a molecular newborn screening for four genetic disorders, including beta-thalassemia (β-thal), glucose-6-phosphate dehydrogenase (G6PD) deficiency, phenylketonuria (PKU), and non-syndromic hearing loss and deafness (NSHL) in this region. A total of 515 newborns were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) developed for screening the mutations causing these four disorders, and then confirmed by Sanger sequencing. The results showed that 48 out of 515 newborns were carriers of mutations related to these four diseases, with a frequency of 1 in 11 (9.32%). The carrier frequencies for each disease are: β-thal 2.72%; G6PD deficiency 1.94%; PKU 0.78% and NSHL 4.47%. The genotyping results by MALDI-TOF MS were concordant with Sanger sequencing results within 30 randomly selected samples. This is the first study that reveals carrier frequencies of these four diseases in Guizhou Province. These data provide valuable information for the genetic counseling and disease prevention in Guizhou and southwest China.