Abstract
We report here a rare female case of pseudohypoparathyroidism with multiple cutaneous osteomas. She also represented both of hypothyroidism without autoantibodies and Albright’s hereditary osteodystrophy (AHO) with characteristic phenotypic disorders such as short stature, obesity, brachydactyly, enamel hypoplasia, and multiple cutaneous osteomas. Ever after 8 years old, she has suffered from severe sensory disturbance on distal bodies and repetitive appearance of cutaneous osteomas because of the instability of serum calcium level. Pseudohypoparathyroidism (PHP) is a heterogeneous disease characterized by PTH resistance and classified as types Ia, Ib, Ic and II, according to its different pathogenesis and phonotype. Recent molecular analyses clarified that heterozygous inactivating Gsα mutation, a cofactor encoded by GNAS1 gene, led to AHO and pseudohypoparathyroidism with PTH resistance. Gsα protein is activated by the intracellular domain of PTH-binding receptor and mediates ATP to cAMP transition, resulting in maintaining calcium homeostasis in PTH-targeted organs. Although it has been estimated that cutaneous ossification is found in 42% of the patients with PHP, the reason for bony formation in cutaneous tissue is unknown. While discussing the correlation between the inactivation of Gsαand osteogenesis, we propose putative mechanisms of cutaneous ossification in AHO with PHP.
