U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Pseudohypoparathyroidism type 1C(PHP1C)

MedGen UID:
420958
Concept ID:
C2932716
Disease or Syndrome
Synonyms: PHP IC; PHP1C; PSEUDOHYPOPARATHYROIDISM, TYPE IC
SNOMED CT: Pseudohypoparathyroidism type 1C (717792007)
Modes of inheritance:
Autosomal dominant inheritance
MedGen UID:
141047
Concept ID:
C0443147
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele.
 
Gene (location): GNAS (20q13.32)
 
Monarch Initiative: MONDO:0012911
OMIM®: 612462
Orphanet: ORPHA79444

Disease characteristics

Excerpted from the GeneReview: Disorders of GNAS Inactivation
Disorders of GNAS inactivation include the phenotypes pseudohypoparathyroidism Ia, Ib, and Ic (PHP-Ia, -Ib, -Ic), pseudopseudohypoparathyroidism (PPHP), progressive osseous heteroplasia (POH), and osteoma cutis (OC). PHP-Ia and PHP-Ic are characterized by: End-organ resistance to endocrine hormones including parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), gonadotropins (LH and FSH), growth hormone-releasing hormone (GHRH), and CNS neurotransmitters (leading to obesity and variable degrees of intellectual disability and developmental delay); and The Albright hereditary osteodystrophy (AHO) phenotype (short stature, round facies, and subcutaneous ossifications) and brachydactyly type E (shortening mainly of the 4th and/or 5th metacarpals and metatarsals and distal phalanx of the thumb). Although PHP-Ib is characterized principally by PTH resistance, some individuals also have partial TSH resistance and mild features of AHO (e.g., brachydactyly). PPHP, a more limited form of PHP-Ia, is characterized by various manifestations of the AHO phenotype without the hormone resistance or obesity. POH and OC are even more restricted variants of PPHP: POH consists of dermal ossification beginning in infancy, followed by increasing and extensive bone formation in deep muscle and fascia. OC consists of extra-skeletal ossification that is limited to the dermis and subcutaneous tissues. [from GeneReviews]
Authors:
Chad R Haldeman-Englert  |  Anna CE Hurst  |  Michael A Levine   view full author information

Additional description

From OMIM
Pseudohypoparathyroidism type Ic (PHP1C) is characterized by resistance to parathyroid hormone (PTH; 168450) as well as to other hormones. It is associated with a constellation of physical features referred to as Albright hereditary osteodystrophy (AHO), which includes short stature, obesity, round facies, subcutaneous ossifications, brachydactyly, and other skeletal anomalies. Some patients have mental retardation. Laboratory studies in patients with PHP Ic show a decreased cellular cyclic AMP (cAMP) response to infused PTH, but no defect in activity of the erythrocyte Gs protein (Mantovani and Spada, 2006).  http://www.omim.org/entry/612462

Clinical features

From HPO
Low urinary cyclic AMP response to PTH administration
MedGen UID:
350345
Concept ID:
C1864105
Finding
Brachydactyly
MedGen UID:
67454
Concept ID:
C0221357
Congenital Abnormality
Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here.
Short metacarpal
MedGen UID:
323064
Concept ID:
C1837084
Anatomical Abnormality
Diminished length of one or more metacarpal bones in relation to the others of the same hand or to the contralateral metacarpal.
Short metatarsal
MedGen UID:
341358
Concept ID:
C1849020
Finding
Diminished length of a metatarsal bone, with resultant proximal displacement of the associated toe.
Obesity
MedGen UID:
18127
Concept ID:
C0028754
Disease or Syndrome
Accumulation of substantial excess body fat.
Short stature
MedGen UID:
87607
Concept ID:
C0349588
Finding
A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Hypocalcemic tetany
MedGen UID:
57499
Concept ID:
C0151940
Disease or Syndrome
Hyperexcitability of the neuromuscular system related to abnormally low level of calcium in the blood, resulting in carpopedal or generalized spasms.
Cognitive impairment
MedGen UID:
90932
Concept ID:
C0338656
Mental or Behavioral Dysfunction
Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering.
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
Osteoporosis
MedGen UID:
14535
Concept ID:
C0029456
Disease or Syndrome
Osteoporosis is a systemic skeletal disease characterized by low bone density and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility. According to the WHO criteria, osteoporosis is defined as a BMD that lies 2.5 standard deviations or more below the average value for young healthy adults (a T-score below -2.5 SD).
Basal ganglia calcification
MedGen UID:
234651
Concept ID:
C1389280
Pathologic Function
The presence of calcium deposition affecting one or more structures of the basal ganglia.
Choroid plexus calcification
MedGen UID:
354924
Concept ID:
C1863184
Pathologic Function
The presence of calcium deposition in the choroid plexus.
Hypocalcemia
MedGen UID:
5705
Concept ID:
C0020598
Disease or Syndrome
An abnormally decreased calcium concentration in the blood.
Hyperphosphatemia
MedGen UID:
39326
Concept ID:
C0085681
Disease or Syndrome
An abnormally increased phosphate concentration in the blood.
Elevated circulating parathyroid hormone level
MedGen UID:
167805
Concept ID:
C0857973
Finding
An abnormal increased concentration of parathyroid hormone.
Enamel hypoplasia
MedGen UID:
3730
Concept ID:
C0011351
Disease or Syndrome
Developmental hypoplasia of the dental enamel.
Delayed eruption of teeth
MedGen UID:
68678
Concept ID:
C0239174
Finding
Delayed tooth eruption, which can be defined as tooth eruption more than 2 SD beyond the mean eruption age.
Round face
MedGen UID:
116087
Concept ID:
C0239479
Finding
The facial appearance is more circular than usual as viewed from the front.
Short neck
MedGen UID:
99267
Concept ID:
C0521525
Finding
Diminished length of the neck.
Depressed nasal bridge
MedGen UID:
373112
Concept ID:
C1836542
Finding
Posterior positioning of the nasal root in relation to the overall facial profile for age.
Full cheeks
MedGen UID:
355661
Concept ID:
C1866231
Finding
Increased prominence or roundness of soft tissues between zygomata and mandible.
Hypogonadism
MedGen UID:
5711
Concept ID:
C0020619
Disease or Syndrome
A decreased functionality of the gonad.
Hypothyroidism
MedGen UID:
6991
Concept ID:
C0020676
Disease or Syndrome
Deficiency of thyroid hormone.
Pseudohypoparathyroidism
MedGen UID:
46178
Concept ID:
C0033806
Disease or Syndrome
Disorders of GNAS inactivation include the phenotypes pseudohypoparathyroidism Ia, Ib, and Ic (PHP-Ia, -Ib, -Ic), pseudopseudohypoparathyroidism (PPHP), progressive osseous heteroplasia (POH), and osteoma cutis (OC). PHP-Ia and PHP-Ic are characterized by: End-organ resistance to endocrine hormones including parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), gonadotropins (LH and FSH), growth hormone-releasing hormone (GHRH), and CNS neurotransmitters (leading to obesity and variable degrees of intellectual disability and developmental delay); and The Albright hereditary osteodystrophy (AHO) phenotype (short stature, round facies, and subcutaneous ossifications) and brachydactyly type E (shortening mainly of the 4th and/or 5th metacarpals and metatarsals and distal phalanx of the thumb). Although PHP-Ib is characterized principally by PTH resistance, some individuals also have partial TSH resistance and mild features of AHO (e.g., brachydactyly). PPHP, a more limited form of PHP-Ia, is characterized by various manifestations of the AHO phenotype without the hormone resistance or obesity. POH and OC are even more restricted variants of PPHP: POH consists of dermal ossification beginning in infancy, followed by increasing and extensive bone formation in deep muscle and fascia. OC consists of extra-skeletal ossification that is limited to the dermis and subcutaneous tissues.
Elevated circulating thyroid-stimulating hormone concentration
MedGen UID:
108325
Concept ID:
C0586553
Finding
Increased concentration of thyroid-stimulating hormone (TSH) in the blood circulation.
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.
Cataract
MedGen UID:
39462
Concept ID:
C0086543
Disease or Syndrome
A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
Follow this link to review classifications for Pseudohypoparathyroidism type 1C in Orphanet.

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...