Two infants with mild, atypical clinical features of Kagami-Ogata syndrome caused by epimutation.

Kagami-Ogata syndrome (KOS) is an imprinting disorder characterized by polyhydramnios, bell-shaped thorax with coat-hanger appearance (curved ribs), respiratory distress, abdominal wall defects, and distinct facial features, together with intellectual developmental delay with special needs. Abnormal expression of the imprinted genes on chromosome 14q32.2 causes KOS. Epimutation with aberrant hypermethylation of the MEG3/DLK1: intergenic differentially methylated region (MEG3/DLK1:IG-DMR) and the MEG3:TSS-DMR is one of the etiologies of KOS. We report two infants with KOS caused by epimutation presenting with some characteristic clinical features, mild clinical course, and almost normal motor and intellectual development. Methylation analysis for ten DMRs related to major imprinting disorders using pyrosequencing with genomic DNA (gDNA) extracted from leukocytes showed abnormally increased methylation levels of the MEG3/DLK1:IG-DMR and MEG3:TSS-DMR in both patients, but lower than those in patients with paternal uniparental disomy chromosome 14 (upd(14)pat). The methylation levels in the DMRs other than both DMRs were within normal range. We also conducted methylation analysis for the MEG3/DLK1:IG-DMR and MEG3:TSS-DMR with gDNA extracted from nails and buccal cells of both patients. Methylation levels in the MEG3:TSS-DMR, particularly in buccal cells, were closer to normal range compared to those in leukocytes. Microsatellite analysis for chromosome 14 and array comparative hybridization analysis showed no upd(14)pat or microdeletion involving the 14q32.2 imprinted region in either patient. A differential mosaic ratio of cells with aberrant methylation of DMRs at the 14q32.2 imprinted region among tissues (connective tissue, lung, and brain) might have led to their atypical clinical features. Further studies of patients with epimutation should further expand the phenotypic spectrum of KOS.

Optimization of surgical timing of congenital diaphragmatic hernia using the quantified flow patterns of patent ductus arteriosus.

PURPOSE: The optimal timing of surgery for congenital diaphragmatic hernia (CDH) is controversial. We aimed to validate our protocol for the timing of CDH repair using the quantified patent ductus arteriosus (PDA) flow pattern. METHODS: This retrospective comparative study analyzed patients with a prenatal diagnosis of isolated CDH between 2007 and 2020. We defined the "LR ratio" as the percentage of velocity-time integral (VTI) of the left-to-right flow of PDA against overall VTI on echocardiography. Since 2010, we followed the decision criterion of performing surgery when LR ratio of > 50% has been achieved in the patients (protocol group). The protocol group (2010-2020) was compared with the historical control group (2007-2009). RESULTS: The average age at surgery was 104.1 ± 175.9 and 37.3 ± 30.6 h in the control and protocol groups, respectively (p = 0.11). Survival rate (88.9% vs. 95.0%, p = 0.53) and the rate of worsening of pulmonary hypertension within 24 h after surgery (22.2% vs. 10.0%, p = 0.57) were not different between the groups. The protocol group had a significantly shorter duration of tracheal intubation (26.9 ± 21.1 vs. 13.3 ± 9.5 days, p = 0.03). CONCLUSION: Our decision criterion might have the advantage of facilitating early and safe surgery for patients with CDH.

Ablepharon and craniosynostosis in a patient with a localized TWIST1 basic domain substitution.

The TWIST family is a group of highly conserved basic helix-loop-helix transcription factors. In humans, TWIST1 haploinsufficiency causes Saethre-Chotzen syndrome, which is characterized by craniosynostosis. Heterozygous localized TWIST1 and TWIST2 basic domain substitutions exert antimorphic effects to cause Sweeney-Cox syndrome, Barber-Say syndrome, and ablepharon-macrostomia syndrome, respectively. Sweeney-Cox syndrome, Barber-Say syndrome, and ablepharon-macrostomia syndrome share the facial features of ablepharon, hypertelorism, underdevelopment of the eyelids, and cheek pads adjacent to the corners of the mouth. Existence of phenotypic overlap between Saethre-Chotzen syndrome and Sweeney-Cox syndrome remains unknown. Herein, we document a male infant with the distinctive facial features of ablepharon, hypertelorism, cheek pads adjacent to the corners of the mouth, and bilateral coronal suture craniosynostosis who had a de novo heterozygous mutation in the basic domain of TWIST1, that is, c.351C>G p.Glu117Asp. The pathogenicity of this variant was supported by in silico and in vivo evidence. Our review showed that Sweeney-Cox syndrome appears to share many characteristics with Barber-Say syndrome and ablepharon-macrostomia syndrome except for craniosynostosis, which is a cardinal feature of Saethre-Chotzen syndrome. An amino acid substitution from Glu117 to Asp, both of which are the sole members of negatively charged amino acids, resulted in a prototypic Sweeney-Cox syndrome phenotype. This suggests that any amino acid substitutions at Glu117 would likely lead to the Sweeney-Cox syndrome phenotype or lethality. The present observation suggests that a localized TWIST1 basic domain substitution, that is, p.Glu117Asp, in TWIST1 may exert a mild antimorphic effect similar to that of haploinsufficiency, leading to craniosynostosis and ablepharon.

Effects of infant flow Bi-NCPAP on apnea of prematurity.

BACKGROUND: Infant flow biphasic nasal continuous positive airway pressure (Bi-NCPAP) and regular NCPAP (Re-NCPAP) are equally useful with respect to the rate of successful weaning from mechanical ventilation. It remains unclear, however, whether Bi-NCPAP or Re-NCPAP is more effective for reducing apnea of prematurity (AOP). METHODS: A multicenter randomized controlled study was conducted of 66 infants assigned to receive Bi-NCPAP and 66 assigned to receive Re-NCPAP for respiratory support after extubation. Primary outcome was the number of AOP events during the 48 h observation period after successful extubation, defined as no reintubation and no adverse events associated with the use of NCPAP during the observation period. The secondary outcome was successful extubation. Reintubation was at the discretion of the attending physician. RESULTS: Baseline characteristics were similar between the two groups. The number of AOP events during the 48 h observation period was significantly lower in infants with Bi-NCPAP than in those with Re-NCPAP (5.2 ± 6.5 vs 10.3 ± 10.9 per infant, respectively; P = 0.002). The rate of successful extubation tended to be greater in those with Bi-NCPAP than in those with Re-NCPAP (92.4%, 61/66 vs 80.3%, 53/66, respectively; P = 0.074). Adverse events occurred in only one of 132 infants: erosive dermatitis developed on the nose after application of Re-NCPAP. The risk of reintubation did not differ significantly between the two groups (7.6%, 5/66 for Bi-NCPAP vs 18.2%, 12/66 for Re-NCPAP; P = 0.117). CONCLUSIONS: Bi-NCPAP was superior to Re-NCPAP for reduction of AOP following extubation.

A neonatal case of thoracoabdominal duplication associated with right congenital diaphragmatic hernia, absent inferior vena cava, and congenital portoazygous shunt: etiopathogenesis and surgical management.

We report on a neonatal case of thoracoabdominal duplication associated with a split notochord syndrome and multiple anomalies. A newborn girl had severe dyspnea and was transferred to our neonatal care unit. At laparotomy, the entire small bowel was herniated into the posterior mediastinum through a defect in the right hemidiaphragm. The small bowel mesentery was firmly fixed to the mediastinum such that a large part of the small bowel could not be repositioned into the abdominal cavity. Imaging studies revealed an absent inferior vena cava with an azygous continuation. The superior mesenteric vein joined the splenic vein to form a portoazygous shunt that ran caudally through the mediastinum and drained into the azygous vein. The patient's intrahepatic portal vein was completely absent. To the best of our knowledge, this is the first reported case of a thoracoabdominal duplication associated with a portoazygous shunt. The etiopathogenesis and surgical management of this complicated case are discussed.