A Girl With Beckwith-Wiedemann Syndrome and Pseudohypoparathyroidism Type 1B Due to Multiple Imprinting Defects.

Abstract

CONTEXT:

Several patients with Beckwith-Wiedemann Syndrome (BWS) with multiple imprinting defects found by genetic analysis have been described. However, only two cases have been described with both genetic and clinical signs and symptoms of multiple diseases caused by imprinting defects.

CASE DESCRIPTION:

The girl in this case presented at the age of 6 months with morbid obesity (body mass index, +7.5 SDS) and a large umbilical hernia. Genetic analysis showed BWS (hypomethylation of the KCNQ1OT1 gene). Calcium homeostasis was normal, and she had no signs of Albright hereditary osteodystrophy. At the age of 10 years, she presented with fatigue, and laboratory analyses showed marked hypocalcemia with signs of PTH resistance, but without evidence for Albright hereditary osteodystrophy, thus suggesting pseudohypoparathyroidism type 1B. Consistent with this diagnosis, methylation analysis of the GNAS complex revealed hypomethylation (about 20%) of the GNAS exon 1A, NESPAS, and GNASXL loci and hypermethylation (100% methylation) of the NESP locus.

CONCLUSIONS:

Imprinting defects at several different loci can occur in some patients, thus causing multiple different diseases. Symptoms of pseudohypoparathyroidism type 1B may be absent at diagnosis of BWS, yet prolonged subclinical hypocalcemia and/or hyperphosphatemia can have negative consequences (eg, intracerebral calcifications, myocardial dysfunction). We therefore suggest that patients with an imprinting disorder should be monitored for elevations in PTH, and epigenetic analysis of the GNAS complex locus should be considered.

• Authors: Boudewijn Bakker, Laura J H Sonneveld, M Claire Woltering, Hennie Bikker, Sarina G Kant
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 100 Issue 11 Pg. 3963-6 (Nov 2015) ISSN: 1945-7197 [Electronic] United States
• PMID: 26367199 (Publication Type: Case Reports, Journal Article)

Chemical References

• Chromogranins
• KCNQ1OT1 long non-coding RNA, human
• Potassium Channels, Voltage-Gated
• RNA, Antisense
• GNAS protein, human
• GTP-Binding Protein alpha Subunits, Gs

Topics

• Beckwith-Wiedemann Syndrome (complications, genetics, metabolism, physiopathology)
• Chromogranins
• DNA Methylation
• Disease Progression
• Down-Regulation
• Epigenesis, Genetic
• Exons
• Female
• GTP-Binding Protein alpha Subunits, Gs (antagonists & inhibitors, genetics, metabolism)
• Genetic Loci
• Genomic Imprinting
• Hernia, Umbilical (etiology)
• Humans
• Hyperphosphatemia (etiology)
• Hypocalcemia (etiology)
• Infant
• Pediatric Obesity (etiology)
• Potassium Channels, Voltage-Gated (genetics, metabolism)
• Pseudohypoparathyroidism (complications, genetics, metabolism, physiopathology)
• RNA, Antisense (metabolism)