Paediatric haematohidrosis: an overview of a rare but clinically distinct condition.

Haematohidrosis is a rare and dramatic condition in which bleeding occurs spontaneously from intact skin. We report the case of a nine-year-old boy with a typical clinical presentation. The case highlights how challenging it can be for medical professionals to recognise and evaluate rare conditions. A review of the literature was performed, showing that haematohidrosis is mainly a paediatric condition. Our case together with findings from the review indicates that treatment with Beta blockers may be effective for treatment of haematohidrosis in children. Conclusion: Paediatric haematohidrosis is a rare, but clinically distinct condition. Treatment with Beta blockers may be tested.

A novel phenotype in N-glycosylation disorders: Gillessen-Kaesbach-Nishimura skeletal dysplasia due to pathogenic variants in ALG9.

A rare lethal autosomal recessive syndrome with skeletal dysplasia, polycystic kidneys and multiple malformations was first described by Gillessen-Kaesbach et al and subsequently by Nishimura et al. The skeletal features uniformly comprise a round pelvis, mesomelic shortening of the upper limbs and defective ossification of the cervical spine. We studied two unrelated families including three affected fetuses with Gillessen-Kaesbach-Nishimura syndrome using whole-exome and Sanger sequencing, comparative genome hybridization and homozygosity mapping. All affected patients were shown to have a novel homozygous splice variant NM_024740.2: c.1173+2T>A in the ALG9 gene, encoding alpha-1,2-mannosyltransferase, involved in the formation of the lipid-linked oligosaccharide precursor of N-glycosylation. RNA analysis demonstrated skipping of exon 10, leading to shorter RNA. Mass spectrometric analysis showed an increase in monoglycosylated transferrin as compared with control tissues, confirming that this is a congenital disorder of glycosylation (CDG). Only three liveborn children with ALG9-CDG have been previously reported, all with missense variants. All three suffered from intellectual disability, muscular hypotonia, microcephaly and renal cysts, but none had skeletal dysplasia. Our study shows that some pathogenic variants in ALG9 can present as a lethal skeletal dysplasia with visceral malformations as the most severe phenotype. The skeletal features overlap with that previously reported for ALG3- and ALG12-CDG, suggesting that this subset of glycosylation disorders constitutes a new diagnostic group of skeletal dysplasias.

Novel alterations in the epigenetic signature of MeCP2-targeted promoters in lymphocytes of Rett syndrome patients.

Rett syndrome (RTT) is a neurodevelopmental disorder with neurological symptoms, such as motor disorders and mental retardation. In most cases, RTT is caused by mutations in the DNA binding protein MeCP2. In mice, MeCP2 gene deletion has been reported to result in genome-wide increased histone acetylation. Transcriptional regulation of neurotrophic factor BDNF and transcription factor DLX5, essential for proper neurogenesis, is further altered in MeCP2-deleted animals. We therefore investigated the chromatin environment of MeCP2 target genes BDNF and DLX5 in lymphocytes from RTT patients and human controls, and analyzed the density of histones H3, H2B and H1, as well as the levels of methylation and acetylation on selected lysines of histone H3. Notably, we found a general increase in the density of histone H3 in RTT patients' lymphocytes compared with controls, and decreased levels of trimethylation of lysine 4 on histone H3 (H3K4me3), a modification associated with transcriptional activation. The levels of acetylation of lysine 9 (H3K9ac) and 27 (H3K27ac) did not show any statistically significant changes when normalized to the decreased histone H3 levels; nevertheless, an average decrease in acetylation was noted. Our results reveal an unexpected alteration of the chromatin state of established MeCP2 target genes in lymphocytes of human subjects with RTT.

Early infantile onset ''congenital'' Rett syndrome variants: Swedish experience through four decades and mutation analysis.

The early infantile onset ''congenital'' variant of Rett syndrome presents with deviations of behavior from very early infancy. Here, we report on a clinical-genetic study in a collected series of 14 Swedish girls with early infantile onset Rett syndrome phenotype. The clinical diagnosis was based on symptom onset before the age of 6 months and the patients fulfilled 3 or more Rett variant criteria and 5 or more supportive criteria. Genotype-phenotype correlation studies in the CDKL5-gene have recently shown clinical associations to early infantile onset Rett variants. Mutation analyses for both the MECP2-gene and the CDKL5-gene were, therefore, performed. Of interest, we found a large deletion covering 2 exons in MECP2, which underlines the importance of MECP2 mutation screening even for the ''atypical'' early infantile onset variants of Rett syndrome. No early infantile onset Rett syndrome patients in this study had the previously well-known hotspot mutations in the MECP2-gene.

Disturbances in cardiorespiratory function during day and night in Rett syndrome.

Rett syndrome causes severe autonomic dysregulation, probably due to brainstem dysfunction. Because the brainstem plays a decisive role in cardiorespiratory regulation during sleep, we investigated cardiorespiratory function in 12 girls with Rett syndrome, day and night, for 1 week in their home environment. Heart rate and breathing were recorded via standard three-lead electrocardiogram. Depth and frequency of respiratory movements were measured via changes in impedance. All children were scored clinically, and the association with cardiorespiratory function was examined. The total recording time for all patients was 1114 hours (535 during wakefulness; 579 during sleep), and 77 +/- 22 hours (median +/- standard error of the mean) per individual. All subjects manifested apnea, shallow breathing, or hypoventilation, when awake and during sleep. A majority had bradycardia or tachycardia. The frequencies of respiratory and heart alarms were similar during wakefulness and sleep. Bradycardia events predominated during sleep. The only significant correlation between clinical score and cardiorespiratory regulation was found for muscular-skeletal function and breathing abnormalities during wakefulness. We conclude that Rett syndrome is characterized by disturbed breathing and heart rate during sleep. The severity of cardiorespiratory dysfunction exhibited marked intra- and interindividual differences.