Real-World Estimates of Adrenal Insufficiency-Related Adverse Events in Children With Congenital Adrenal Hyperplasia

BACKGROUND

Although congenital adrenal hyperplasia (CAH) is known to be associated with adrenal crises (AC), its association with patient- or clinician-reported sick day episodes (SDE) is less clear.

METHODS

Data on children with classic 21-hydroxylase deficiency CAH from 34 centers in 18 countries, of which 7 were Low or Middle Income Countries (LMIC) and 11 were High Income (HIC), were collected from the International CAH Registry and analyzed to examine the clinical factors associated with SDE and AC.

RESULTS

A total of 518 children-with a median of 11 children (range 1, 53) per center-had 5388 visits evaluated over a total of 2300 patient-years. The median number of AC and SDE per patient-year per center was 0 (0, 3) and 0.4 (0.0, 13.3), respectively. Of the 1544 SDE, an AC was reported in 62 (4%), with no fatalities. Infectious illness was the most frequent precipitating event, reported in 1105 (72%) and 29 (47%) of SDE and AC, respectively. On comparing cases from LMIC and HIC, the median SDE per patient-year was 0.75 (0, 13.3) vs 0.11 (0, 12.0) (P < 0.001), respectively, and the median AC per patient-year was 0 (0, 2.2) vs 0 (0, 3.0) (P = 0.43), respectively.

CONCLUSIONS

The real-world data that are collected within the I-CAH Registry show wide variability in the reported occurrence of adrenal insufficiency-related adverse events. As these data become increasingly used as a clinical benchmark in CAH care, there is a need for further research to improve and standardize the definition of SDE.

Long-range conserved non-coding SHOX sequences regulate expression in developing chicken limb and are associated with short stature phenotypes in human patients

Defects in long-range regulatory elements have recently emerged as previously underestimated factors in the genesis of human congenital disorders. Léri-Weill dyschondrosteosis is a dominant skeletal malformation syndrome caused by mutations in the short stature homeobox gene SHOX. We have analysed four families with Léri-Weill dyschondrosteosis with deletions in the pseudoautosomal region but still with an intact SHOX coding region. Using fluorescence in situ hybridization and single nucleotide polymorphism studies, we identified an interval of approximately 200 kb that was deleted in all tested affected family members but retained in the unaffected members and in 100 control individuals. Comparative genomic analysis of this interval revealed eight highly conserved non-genic elements between 48 and 215 kb downstream of the SHOX gene. As mice do not have a Shox gene, we analysed the enhancer potential in chicken embryos using a green fluorescent protein reporter construct driven by the beta-globin promoter, by in ovo electroporation of the limb bud. We observed cis-regulatory activity in three of the eight non-genic elements in the developing limbs arguing for an extensive control region of this gene. These findings are consistent with the idea that the deleted region in the affected families contains several distinct elements that regulate Shox expression in the developing limb. Furthermore, the deletion of these elements in humans generates a phenotype apparently undistinguishable to those patients identified with mutations in the SHOX coding region and, for the first time, demonstrates the potential of an in vivo assay in chicken to monitor putative enhancer activity in relation to human disease.