Endocrine and Growth Abnormalities in 4H Leukodystrophy Caused by Variants in POLR3A, POLR3B, and POLR1C

CONTEXT

4H or POLR3-related leukodystrophy is an autosomal recessive disorder typically characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism, caused by biallelic pathogenic variants in POLR3A, POLR3B, POLR1C, and POLR3K. The endocrine and growth abnormalities associated with this disorder have not been thoroughly investigated to date.

OBJECTIVE

To systematically characterize endocrine abnormalities of patients with 4H leukodystrophy.

DESIGN

An international cross-sectional study was performed on 150 patients with genetically confirmed 4H leukodystrophy between 2015 and 2016. Endocrine and growth abnormalities were evaluated, and neurological and other non-neurological features were reviewed. Potential genotype/phenotype associations were also investigated.

SETTING

This was a multicenter retrospective study using information collected from 3 predominant centers.

PATIENTS

A total of 150 patients with 4H leukodystrophy and pathogenic variants in POLR3A, POLR3B, or POLR1C were included.

MAIN OUTCOME MEASURES

Variables used to evaluate endocrine and growth abnormalities included pubertal history, hormone levels (estradiol, testosterone, stimulated LH and FSH, stimulated GH, IGF-I, prolactin, ACTH, cortisol, TSH, and T4), and height and head circumference charts.

RESULTS

The most common endocrine abnormalities were delayed puberty (57/74; 77% overall, 64% in males, 89% in females) and short stature (57/93; 61%), when evaluated according to physician assessment. Abnormal thyroid function was reported in 22% (13/59) of patients.

CONCLUSIONS

Our results confirm pubertal abnormalities and short stature are the most common endocrine features seen in 4H leukodystrophy. However, we noted that endocrine abnormalities are typically underinvestigated in this patient population. A prospective study is required to formulate evidence-based recommendations for management of the endocrine manifestations of this disorder.

Latin American Registry of dialysis and renal transplantation: 1993 annual dialysis data report

BACKGROUND

The Latin American Registry of Dialysis and Transplantation was created in October 1991 and comprises the National Societies of Nephrology from 21 countries with a total population of 468.56 million inhabitants.

METHODS

This report includes data from 21,181 patients from Argentina, Brazil, Chile, El Salvador, Panama, Paraguay, Peru, Puerto Rico, Uruguay, and Venezuela who were receiving chronic dialysis treatment during 1993. Data was collected by individual patient questionnaires except from Chile and Brazil where the data was obtained from a local centre questionnaire.

RESULTS

The prevalence rate averaged 131.1 per million population. The mean age of the 8972 incident patients was 50.5 years, with 58.2% males. The more frequent causes of renal failure were glomerulopathies (22.6%), vascular nephropathy (20.9%) and diabetes (16.9%). Haemodialysis was the most used treatment (88.3%). Gross mortality was 21.1% and the more frequent causes of death were cardiac complications and infections. The analysis of mortality risk factors using a logistic regression model showed that diabetics patients older than 65 years had the highest probability of death (43.0%) and patients with glomerulonephritis, younger than 65 years had the lowest (8.0%). The adjusted mortality rate was 241 deaths/1000 patient-years at risk when the USRDS 1987-1989 white mortality rate by age groups and primary diseases was used as standard.

CONCLUSION

In spite of the economic difficulties, very important efforts have been made to treat ESRD patients and gross mortality statistics in some countries are similar to those reported by other regional registries.