Progressive osseous heteroplasia: a model for the imprinting effects of GNAS inactivating mutations in humans.

Context: Heterozygous GNAS inactivating mutations are known to induce pseudohypoparathyroidism type 1a when maternally inherited and pseudopseudohypoparathyroidism when paternally inherited. Progressive osseous heteroplasia (POH) is a rare disease of ectopic bone formation, and studies in different families have shown that POH is also caused by paternally inherited GNAS mutations.

Objective: Our purpose was to characterize parental origin of the mutated allele in de novo cases of POH and to draw phenotype/genotype correlations according to maternal or paternal transmission of a same GNAS mutation.

[Biphosphonates and osteogenesis imperfecta in children].

Used for more than 10 years in addition to physiotherapy, orthopaedic surgery and rehabilitation, biphosphonate therapy has transformed the management of children with severe or moderate form of osteogenesis imperfecta. The authors of this article report indications, administration's way, duration and safety of biphosphonate therapy with uncertainties about persistence in skeleton for many years.

A novel Asp344Val substitution in the fibrinogen gamma chain (fibrinogen Caen) causes dysfibrinogenemia associated with thrombosis.

A 5-year-old boy was hospitalized for acute appendicitis. Routine preoperative hemostasis screening resulted in a diagnosis of dysfibrinogenemia. Fifteen days after the operation the patient was re-hospitalized for deep vein thrombosis.