Objectives: To analyze the results of neonatal screening for congenital hypothyroidism (CH) and hyperphenylalaninemia (HPA) in Zhejiang province from 1999 to 2022.
Methods: A total of 11 922 318 newborns were screened from September 1999 and December 2022 in Zhejiang province. The blood thyroid stimulating hormone (TSH) levels were measured by a fluorescence method and blood phenylalanine (Phe) levels were measured by fluorescence method or tandem mass spectrometry. TSH≥9 μIU/mL was considered positive for CH, while Phe>120 μmol/L and/or Phe/Tyr ratio>2.0 were considered positive for HPA. The positive newborns in screening were recalled, and the gene variations were detected by high-throughput sequencing and MassARRAY tests.
Results: The overall neonatal screening rate during 1999-2022 was 89.41% (11 922 318/13 333 929) and the screening rate was increased from 6.46% in 1999 to 100.0% in 2022. A total of 8924 cases of CH were diagnosed among screened newborns with an incidence rate of 1/1336. A total of 563 cases of HPA were diagnosed, including 508 cases of classic phenylketonuria (cPKU) and 55 cases of tetrahydrobiopterin deficiency (BH4D), with an incidence rate of 1/21 176. Ninety-seven out of 8924 cases of CH underwent genetic analysis. Gene mutations were detected in 9 CH related genes, the highest frequency mutations were found in DUOX2 gene (69.0%) with c.3329G>A (p.R1110Q) (18.2%) and c.1588A>T (p.K530X) (17.3%) as the hotspot mutations. There were 81 PAH gene variants detected in a total of 250 cases of cPKU, and c728G>A (p.R243Q) (24.4%), c.721C>T (p.R241C) (15.0%) were the hotspot mutations. Meanwhile 7 novel variants in PAH gene were detected: c.107C>A (p.S36*), c.137G>T (p.G46V), c.148A>G(p.K50E), c.285C>T (p.I95I), c.843-10delTTCC, exon4-7del and c.1066-2A>G. There were 12 PTS gene variants detected in 36 cases of BH4D, and c.259C>T (p.P87S) (31.9%) was the hotspot mutation.
Conclusions: The incident of CH has increased from 1999 to 2022 in Zhejiang province, and it is higher than that of national and global levels; while the incidence of HPA is similar to the national average. DUOX2 gene variation is the most common in CH patients; c.728G>A (p.R243Q) is the hotspot mutation in cPKU patients, while c.259C>T (p.P87S) is the hotspot mutation in BH4D patients.
目的: 了解浙江省新生儿先天性甲状腺功能减退症（CH）及高苯丙氨酸血症（HPA）的筛查及发病情况。方法: 收集1999年9月至2022年12月浙江省新生儿疾病筛查中心11 922 318名新生儿血促甲状腺素（TSH）及苯丙氨酸（Phe）检测的资料。其中，血TSH浓度采用荧光法检测，血Phe浓度采用荧光法或串联质谱法检测。TSH在9 μIU/mL及以上的新生儿为CH筛查阳性，血Phe浓度超过120 μmol/L和（或）血Phe与酪氨酸（Tyr）比值大于2.0为HPA筛查阳性，召回复查。采用高通量测序和MassARRAY技术检测基因变异。结果: 1999—2022年共筛查新生儿11 922 318名，总筛查率为89.41%，筛查率由1999年6.46%提升至2022年的100.00%。检出CH患儿8924例，患病率为1/1336，检出HPA患儿563例，患病率为1/21 176，其中508例为经典型苯丙酮尿症（cPKU），55例为四氢生物蝶呤缺乏症（BH4D）。97例CH患儿完善基因检测，检出9种CH相关基因，双氧化酶2（DUOX2）基因检出频率最高（69.0%），其中c.3329G>A（p.R1110Q）（18.2%）和c.1588A>T（p.K530X）（17.3%）为热点突变。250例cPKU患者中检出81种苯丙氨酸羟化酶（PAH）基因变异，其中c728G>A（p.R243Q）（24.4%）和c.721C>T（p.R241C）（15.0%）为热点突变，7种为新发变异：c.107C>A（p.S36*）、c.137G>T（p.G46V）、c.148A>G（p.K50E）、c.285C>T（p.I95I）、c.843-10delTTCC、exon4-7del和c.1066-2A>G。36例BH4D患者中检出12种6-丙酮酰四氢蝶呤合成酶（PTS）基因变异，热点突变为c.259C>T（p.P87S）（31.9%）。结论: 浙江省新生儿筛查率逐年升高，CH发病率明显增高，HPA发病率与全国平均水平接近。DUOX2基因变异为CH患儿最常见基因变异，c728G>A（p.R243Q）为cPKU患者的热点突变，c.259C>T（p.P87S）为BH4D患者的热点突变。.
Keywords: Congenital hypothyroidism; Gene variation; Hyperphenylalaninemia; Newborn screening.