Neonatal pseudohypoparathyroidism

Narang, Manish; Salota, Rashim; Sachdev, Sudeep Singh

doi:10.1007/bf02758270

Cited by 10 publications

(7 citation statements)

References 3 publications

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“…Despite being congenital, only a few cases of PHP in the neonatal period have been reported [24]. Clinical manifestations typically occur later in childhood, suggesting that PTH resistance and consequent changes in serum calcium and phosphate levels develop gradually.…”

Section: Investigationsmentioning

confidence: 99%

Pseudohypoparathyroidism type 1B – a rare cause of tetany: case report

Garcia

Correia

Lopes

2017

Paediatrics and International Child Health

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Pseudohypoparathyroidism (PHP) is a rare group of disorders characterised by end-organ resistance to the parathyroid hormone (PTH). A 16-year-old boy presented with a 2-year history of involuntary dystonic movements involving mainly the left hand, initially after writing and later during physical exercise. Serum calcium was 1.37 mmol/L (2.20-2.69), phosphate 2.1 mmol/L (0.8-1.45) and PTH 302 ng/L (12-88). CT scan of the head demonstrated multiple subcortical and diffuse basal ganglia calcifications. Genetic analysis confirmed a methylation defect in the GNAS cluster on chromosome 20q13.32 which established the diagnosis. Treatment with calcitriol and calcium carbonate led to complete remission of symptoms. Causes of hypocalcaemia should be considered in evaluating patients with movement disorders. The diagnosis of PHP-1B is challenging but the overall prognosis is excellent.

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Section: Investigationsmentioning

confidence: 99%

Pseudohypoparathyroidism type 1B – a rare cause of tetany: case report

Garcia

Correia

Lopes

2017

Paediatrics and International Child Health

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“…On the other hand, several cases of PHP‐Ia with documented GNAS mutations have been reported in whom PTH levels were elevated during infancy . Moreover, although the presence of GNAS mutations was not investigated, hypocalcemia owing to PTH resistance has been reported in a substantial number of infants and newborns . Hence, it has remained unclear whether the renal proximal tubular PTH resistance caused by maternal loss of Gαs manifests itself during early postnatal life.…”

Section: Introductionmentioning

confidence: 99%

“…(27)(28)(29)(30)(31)(32) Moreover, although the presence of GNAS mutations was not investigated, hypocalcemia owing to PTH resistance has been reported in a substantial number of infants and newborns. (33)(34)(35)(36)(37)(38)(39)(40)(41) Hence, it has remained unclear whether the renal proximal tubular PTH resistance caused by maternal loss of Gas manifests itself during early postnatal life. This is an important question, considering that the paternal Gas silencing has an important role in the development of this biochemical defect.…”

Section: Introductionmentioning

confidence: 99%

Postnatal Establishment of Allelic Gαs Silencing as a Plausible Explanation for Delayed Onset of Parathyroid Hormone Resistance Owing to Heterozygous Gαs Disruption

Turan

Fernández-Rebollo

Aydın

et al. 2013

Journal of Bone and Mineral Research

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Pseudohypoparathyroidism type-Ia (PHP-Ia), characterized by renal proximal tubular resistance to parathyroid hormone (PTH), results from maternal mutations of GNAS that lead to loss of Gαs activity. Gαs expression is paternally silenced in the renal proximal tubule, and this genomic event is critical for the development of PTH-resistance, as patients display impaired hormone action only if the mutation is inherited maternally. The primary clinical finding of PHP-Ia is hypocalcemia, which can lead to various neuromuscular defects including seizures. PHP-Ia patients frequently do not present with hypocalcemia until after infancy, but it has remained uncertain whether PTH-resistance occurs in a delayed fashion. Analyzing reported cases of PHP-Ia with documented GNAS mutations and mice heterozygous for disruption of Gnas, we herein determined that the manifestation of PTH-resistance caused by the maternal loss of Gαs, i.e. hypocalcemia and elevated serum PTH, occurs after early postnatal life. To investigate whether this delay could reflect gradual development of paternal Gαs silencing, we then analyzed renal proximal tubules isolated by laser capture microdissection from mice with either maternal or paternal disruption of Gnas. Our results revealed that, whereas expression of Gαs mRNA in this tissue is predominantly from the maternal Gnas allele at weaning (three-weeks postnatal) and in adulthood, the contributions of the maternal and paternal Gnas alleles to Gαs mRNA expression are equal at postnatal day 3. In contrast, we found that paternal Gαs expression is already markedly repressed in brown adipose tissue at birth. Thus, the mechanisms silencing the paternal Gαs allele in renal proximal tubules are not operational during early postnatal development, and this finding correlates well with the latency of PTH-resistance in patients with PHP-Ia.

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“…This is important because elevated PTH levels in pa ents with PHP could cause increased bone remodelling and can lead to hyperparathyroid bone disease 5 . In our case child was managed with calcitriol (0.25 μg/day) along with calcium supplements and child responded well with normal serum calcium and phosphorus levels and was seizure free.…”

Section: Discussionmentioning

confidence: 99%

Pseudohypoparathyroidism as a Cause of Refractory Seizures

Singh¹,

Thapar²,

Malhotra³

2014

J. Nepal Paedtr. Soc.

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Pseudohypoparathyroidism is a genetic disorder that is similar to hypoparathyroidism, but which results from the body's lack of response to parathyroid hormone rather than its decreased production. Serum level of immunoreactive Parathormone are elevated instead. We report a four month old infant in status epilepticus associated with hypocalcemia, hyperphosphatemia and raised parathyroid hormone level. Hypocalcemia was resistant to calcium therapy initially but responded to vitamin D analogue therapy leading to diagnosis of Pseudohypoparathyroidism.

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Neonatal pseudohypoparathyroidism

Cited by 10 publications

References 3 publications

Pseudohypoparathyroidism type 1B – a rare cause of tetany: case report

Pseudohypoparathyroidism type 1B – a rare cause of tetany: case report

Postnatal Establishment of Allelic Gαs Silencing as a Plausible Explanation for Delayed Onset of Parathyroid Hormone Resistance Owing to Heterozygous Gαs Disruption

Pseudohypoparathyroidism as a Cause of Refractory Seizures

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