Pseudopseudohypoparathyroidism

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Pseudopseudohypoparathyroidism
Classification and external resources
ICD-9 275.49
OMIM 612463
DiseasesDB 29783
MeSH D011556

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.

It is sometimes considered a variant of Albright hereditary osteodystrophy.[1]

It was characterized in 1952 by Fuller Albright as "pseudo-pseudohypoparathyroidism" (with hyphen).[2][3]

Presentation[edit]

Pseudopseudohypoparathyroidism can be best understood by comparing it to other conditions:

Condition Appearance PTH levels Calcitriol Calcium Phosphates Imprinting
Hypoparathyroidism Normal Low Low Low High Not applicable
Pseudohypoparathyroidism Type 1A Skeletal defects High Low Low High Gene defect from mother (GNAS1)
Type 1B Normal High Low Low High Gene defect from mother (GNAS1 and STX16)
Type 2 Normal High Low Low High  ?
Pseudopseudohypoparathyroidism Skeletal defects Normal Normal Normal[4] Normal Gene defect from father

Hormone resistance is not present in pseudopseudohypoparathyroidism.[5] Short stature may be present.[6] Obesity is less common in pseudopseudohypoparathyroidism than in pseudohypoparathyroidism.[7] Osteoma cutis may be present.[8]

Inheritance[edit]

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,[9] but pseudopseudohypoparathyroidism has normal calcium homeostasis because of the normal maternal allele in the kidney.[10]

Linguistic significance[edit]

At 30 letters, the English name of the disorder is one of the candidates for being the longest word in English.[11]

See also[edit]

References[edit]

  1. ^ Solomon SS, Kerlan RM, King LE, Jones GM, Hashimoto K (January 1975). "Pseudopseudohypoparathyroidism with fibrous dysplasia". Arch Dermatol 111 (1): 90–3. doi:10.1001/archderm.111.1.90. PMID 1119829. 
  2. ^ Philip R. Beales; I. Sadaf Farooqi; Stephen O'Rahilly (12 September 2008). The genetics of obesity syndromes. Oxford University Press US. pp. 91–. ISBN 978-0-19-530016-1. Retrieved 30 October 2010. 
  3. ^ ALBRIGHT F, FORBES AP, HENNEMAN PH (1952). "Pseudo-pseudohypoparathyroidism". Trans. Assoc. Am. Physicians 65: 337–50. PMID 13005676. 
  4. ^ Shahid Hussain; Sharif Aaron Latif; Adrian Hall (1 July 2010). Rapid Review of Radiology. Manson Publishing. pp. 262–. ISBN 978-1-84076-120-7. Retrieved 30 October 2010. 
  5. ^ Mouallem M, Shaharabany M, Weintrob N, et al. (February 2008). "Cognitive impairment is prevalent in pseudohypoparathyroidism type Ia, but not in pseudopseudohypoparathyroidism: possible cerebral imprinting of Gsalpha". Clin. Endocrinol. (Oxf) 68 (2): 233–9. doi:10.1111/j.1365-2265.2007.03025.x. PMID 17803690. 
  6. ^ Riggs JE (July 1997). "Military service and pseudopseudohypoparathyroidism: recognizing red flags for rare medical conditions". Mil Med 162 (7): 510–2. PMID 9232985. 
  7. ^ Long DN, McGuire S, Levine MA, Weinstein LS, Germain-Lee EL (March 2007). "Body mass index differences in pseudohypoparathyroidism type 1a versus pseudopseudohypoparathyroidism may implicate paternal imprinting of Galpha(s) in the development of human obesity". J. Clin. Endocrinol. Metab. 92 (3): 1073–9. doi:10.1210/jc.2006-1497. PMID 17164301. 
  8. ^ Jeong KH, Lew BL, Sim WY (May 2009). "Osteoma cutis as the presenting feature of albright hereditary osteodystrophy associated with pseudopseudohypoparathyroidism". Ann Dermatol 21 (2): 154–8. doi:10.5021/ad.2009.21.2.154. PMC 2861203. PMID 20523775. 
  9. ^ Lebrun M, Richard N, Abeguilé G, et al. (June 2010). "Progressive osseous heteroplasia: a model for the imprinting effects of GNAS inactivating mutations in humans". J. Clin. Endocrinol. Metab. 95 (6): 3028–38. doi:10.1210/jc.2009-1451. PMID 20427508. 
  10. ^ David Terris; Christine G. Gourin (15 November 2008). Thyroid and Parathyroid Diseases: Medical and Surgical Management. Thieme. pp. 193–. ISBN 978-1-58890-518-5. Retrieved 30 October 2010. 
  11. ^ "What is the longest English word?". AskOxford. Oxford Dictionaries Online. 

External links[edit]