Zellweger syndrome caused by PEX6 gene variation in 2 cases and literature review / 中华儿科杂志

Objective: To summarize the clinical features and genetic characteristics of Zellweger spectrum disorder caused by PEX6 gene variation. Methods: This was a case series research. Clinical date and genetic results of 2 neonatal cases of Zellweger syndrome caused by PEX6 gene variation in Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science & Technology and Affiliated Hospital of Guangdong Medical University from July 2021 to July 2022 were retrospectively collected and analyzed. Literature up to August 2023 was searched from electronic databases of China National Knowledge Infrastructure (CNKI), Wanfang Data and PubMed with the combined keywords of "Zellweger syndrome" "Zellweger spectrum disorder", and "PEX6 gene" both in Chinese and English. The main clinical features and genetic characteristics of Zellweger spectrum disorder caused by PEX6 gene variation were summarized. Results: The 2 male neonates both developed clinical manifestations as dyspnea, hypotonia, feeding difficulties, enlarged fontanelle, and high palatine arch after birth. Biochemical parameters indicated elevated bile acids, and the cranial ultrasound showed the enlarged bilateral ventricles and subependymal cyst in both 2 neonates. Zellweger syndrome was confirmed by whole exome sequencing, and the results revealed PEX6 gene variation in the 2 neonates, including compound heterozygous variants c.315G>A and c.2095-3T>G, and homozygous variant c.506_507del. Case 1 was hospitalized for 5 days, and case 2 for 32 days; they both died shortly after being discharged (the specific time is unknown). Literature review found 26 patients, including 2 neonates in this study, with Zellweger spectrum disorder caused by PEX6 gene defect reported in 1 Chinese article and 11 English articles. Clinical features included hearing loss (19 cases), developmental delay (19 cases), vision impairment (19 cases), elevated very long chain fatty acids (17 cases), brain malformations (15 cases), hypotonia (12 cases), hepatic insufficiency (12 cases), distinctive facies (10 cases), and dental impairment (9 cases). Compound heterozygous variations dominated the variation types (15 cases), and the frameshift variations (16 cases) were the main pathogenic variations. Conclusions: Zellweger spectrum disorder should be considered when neonates show hypotonia, feeding difficulty, distinctive facial appearance, brain malformations and failure of hearing screening, or when older children show retinitis pigmentosa, sensorineural hearing loss, amelogenesis imperfecta and developmental delays. Detection of genetic variation in the PEX gene is crucial for definitive diagnosis.

Effect of breastfeeding on insulin sensitivity in infants with intrauterine growth retardation: a follow-up study / 中国当代儿科杂志

OBJECTIVE@#To study insulin sensitivity and the serum level of adiponectin in infants with intrauterine growth retardation (IUGR) and the effect of breastfeeding on the insulin sensitivity through a follow-up study.@*METHODS@#A total of 106 full-term IUGR infants who were hospitalized from October 2014 to October 2018 were enrolled as the IUGR group, and 90 full-term appropriate for gestational age (AGA) infants who were born during the same period of time were enrolled as the AGA group. Birth weight and body length were recorded. Serum levels of fasting blood glucose (FBG), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), insulin, and adiponectin were measured on day 7 after birth. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. According to the feeding pattern, the IUGR group was further divided into a breastfeeding group with 37 infants and a formula feeding group with 42 infants. The above serum indices and growth indices were also measured at the age of 3 and 6 months.@*RESULTS@#Compared with the AGA group, the IUGR group had significantly increased levels in serum insulin and HOMA-IR and a significantly decreased level of adiponectin (P0.05). In the breastfeeding group, serum insulin and HOMA-IR decreased and adiponectin level increased over the time of breastfeeding (P<0.05).@*CONCLUSIONS@#Insulin sensitivity decreases in the early stage after birth in IUGR infants, and breastfeeding can improve insulin sensitivity.