Pseudopseudohypoparathyroidism (pseudoPHP) is an inherited disorder, named for its similarity to pseudohypoparathyroidism in presentation. The term pseudopseudohypoparathyroidism is used to describe a condition where the individual has the phenotypic appearance of pseudohypoparathyroidism type 1a, but is biochemically normal.
Hormone resistance is not present in pseudopseudohypoparathyroidism.Short stature may be present.Obesity is less common in pseudopseudohypoparathyroidism than in pseudohypoparathyroidism.Osteoma cutis may be present.
A mother who has inherited pseudopseudohypoparathyroidism from her father may in turn pass along pseudohypoparathyroidism 1A to her children as the imprinting pattern on the inherited paternal chromosome will be changed to the maternal pattern in the mother's ovum during meiosis.
Pseudopseudohypoparathyroidism and pseudohypoparathyroidism both involve the same GNAS gene, but pseudopseudohypoparathyroidism has normal calcium homeostasis because of the normal maternal allele in the kidney.