[Phenotypes and ATP7B gene variants in 316 children with Wilson disease].

Objectives: To summarize the clinical phenotypes and the variation spectrum of ATP7B gene in Chinese children with Wilson's disease (WD) and to investigate their significance for early diagnosis. Methods: Retrospective analysis was performed on the clinical data of 316 children diagnosed as WD in Guangzhou Women and Children's Medical Center during the period from January 2010 to June 2021. The general situations, clinical manifestations, lab test results, imaging examinations, and ATP7B gene variant characteristics were collected. The patients were divided into asymptomatic WD group and symptomatic WD group based on the presence or absence of clinical symptoms at the time that WD diagnosis was made. The χ2 test, t test or Mann-Whitney U test were used to compare the differences between groups. Results: Among the 316 children with WD, 199 were males and 117 were females, with the age of 5.4 (4.0, 7.6) years at diagnosis; 261 cases (82.6%) were asymptomatic with the age of 4.9 (3.9, 6.4) years; whereas 55 cases (17.4%) were symptomatic with the age of 9.6 (7.3, 12.0) years. The main symptoms invloved liver, kidney, nervous system, or skin damage. Of all the patients, 95.9% (303/316) had abnormal liver function at diagnosis; 98.1% (310/316) had the serum ceruloplasmin lever lower than 200 mg/L; 97.7% (302/309) had 24-hour urine copper content exceeding 40 µg; only 7.4% (23/310) had positive corneal K-F rings, 8.2% (23/281) had abnormal MRI signals in the lenticular nucleus, and all of them had symptoms of damage in liver, kidney or nervous system. Compared with the group of symptomatic WD, asymptomatic group had higher levels of serum alanine aminotransferase and lower levels ceruloplasmin and 24-hour urine copper [(208±137) vs. (72±78) U/L, (55±47) vs. (69±48) mg/L, 103 (72, 153) vs. 492 (230, 1 432) µg; t=9.98, -1.98, Z=-4.89, all P<0.001]. Among the 314 patients completing genetic sequencing, a total of 107 mutations in ATP7B gene were detected, of which 10 are novel variants, and 3 cases (1.0%) had large heterozygous deletion (exons 10 to exon 11) in ATP7B gene. The percentage of missense mutation in asymptomatic WD children was significantly higher than that in symptomatic WD (81.5% (422/518) vs. 69.1% (76/110), χ²=8.47, P<0.05). WD patients carrying homozygous variant of c.2 333G>T had significantly low levels of ceruloplasmin than those not carrying this variant ((23±5) vs. (61±48) mg/L, t=-2.34, P<0.001). Conclusions: The elevation of serum ALT is an important clue for early diagnosis of WD in children, while serum ceruloplasmin and 24-hour urine copper content are specific markers for early diagnosis of WD. In order to confirm the diagnosis of WD, it is necessary to combine the Sanger sequencing with multiplex ligation-dependent probe amplification or other testing technologies.

[Genetic etiology of newborn deaths].

Objective: To explore the genetic etiologies of newborn deaths. Methods: A total of 98 newborns who were recruited to the Neonatal Genome Project of the Children's Hospital of Fudan University and died in the hospital from January 2018 to August 2020 were enrolled in this study. The genetic information and the interventions based on the genetic findings were retrospectively analyzed. T-test, Mann-Whitney U test, Chi square test and Fisher's exact probability test were used to compare the demographic features and clinical characteristics between the patients with or without a genetic finding. Results: Among 98 newborns (55 males and 43 females), there were 63 preterm and 35 term infants, with a gestational age of (33±5) weeks, a birth weight of (2 107±975) g and the age at death of 12 (2,34) days. Sixteen (16%)patients were identified with genetic variants, including 11 with single nucleotide variants, 4 with copy number variants and 1 with both single nucleotide variant and copy number variant. The detected single nucleotide variants were spanning 12 genes, among which 3 were multiple disorders-related, 2 metabolic disorder-related, 2 hematological disorder-related, 2 respiratory disorder-related, 2 cardiovascular disorder-related and 1 skeletal disorder-related. The patients with a positive genetic finding had significant differences in the birth weight ((2 605±940) vs. (2 009±957) g, t=2.283, P=0.025), the gestational age ((36±5) vs. (33±5) weeks, t=2.131, P=0.036), the age at death ((37 (5, 69) vs. 11 (2, 29) days, Ζ=-2.245, P=0.025) and the history of asphyxia at birth (1/16 vs. 46% (38/82), P=0.002)when compared to those without a genetic finding. In addition, the genetic etiology rates of patients who were born term or with a birth weight ≥ 2 000 g were significantly higher than those who were born preterm (29% (10/35) vs. 10% (6/63), P=0.022) or with a birth weight<2 000 g (25% (13/51) vs. 7% (3/46), χ2=5.016,P=0.025), respectively. Six cases were medically actionable based on the genetic findings and the treatments included special diet, applying specific medicine, hematopoietic stem cell transplantation and lung transplantation. Conclusions: Genetic etiologies are not rare in newborn deaths and mainly associated with metabolic disorder, multi-system disorders, hematological disorder, respiratory disorder, cardiovascular disorder and skeletal disorder. Some findings are medically actionable, based on which the specific treatments could be scheduled timely. A genetic etiology should be investigated in newborn deaths especially in those who are term birth or with a birth weight ≥2 000 g or without a history of asphyxia at birth.