Common Parathyroid Disorders in Children

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Common Parathyroid Disorders in Children

• Dr Sarar Mohamed
• FRCPCH (UK), MRCP (UK), CCST (Ire), CPT (Ire),
• DCH (Ire), MD
• Consultant Paediatric Endocrinologist
  Metabolic Physician
• Associate Professor of Pediatrics
• King Saud University

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Agenda

• Calcium homeostasis
• Causes of hypocalcaemia
• Rickets
• hypercalcaemia

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Key-players of calcium metabolism

• Calcium Phosphates
• Parathyroid hormone (PTH).
• Cholecalciferol (Vit.D3) and Calcitriol
• Estrogen and other Sex hormones.
• Calcitonin.

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PARATHYROID HORMONE Function of PTH 1-raises
the level of calcium in the blood 2-decreases
levels of blood phosphate. 3-Partially
antagonistic to calcitonin
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PARATHYROID HORMONE

• Secreation stimulated by fall in serum Ca.
• mobilize calcium from bone
• Increases renal reabsorption of ca
• ?decreases renal clearance of calcium
• ? increase calcium absorption - intestine

Calcium homeostasis
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Vitamin D

• Fat soluble vitamin
• Synthesised in skin
• Food sources include fish oils

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Vitamin D

• The active hormone is 1,25(OH)2D3
• It increases absorption of calcium from gut.
• It increases reabsorption of ca from kidney.

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Calcitonin

• It is a calcium lowering hormone
• Secreted by Thyroid C cells

Anti - PTH
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Target Organs
Kidney
G.I.Tract
Bone
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Dysfunction of parathyroid Gland

• 1. Too little parathyroid hormone
  hypoparahypothyroidism
• causes low serum calcium and high phosphate
• 2. Too much parathyroid hormone
  hyperparahyperthyroidism
• causes high calcium and low phosphate

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Calcium profile

• To diagnose a metabolic bone disease
• calcium
• Phosphate
• Alkaline phosphatase
• Parathyroid hormone
• Vitamin D
• Urinary calcium and phospherus

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Causes of hypocalcaemia

• Rickets
• Hypopararthyroidism
• Psuedohypopararthyroidism
• Familial hypocalcaemia
• Renal failure
• Drugs phenytoin
• Maternal diabetes
• Premarurity
• DiGoerge syndrome

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Rickets

• Reduced mineralization
• of bone matrix due to calcium deficiency.

rickets results when the osteoid does not have
mineral.
Calcium deficiency/Vit D deficiency
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Deficiency of Vit. D

• Dietary lack of the vitamin
• Insufficient ultraviolet skin exposure
• Malabsorption of fats and fat-soluble vitamins-
  A, D, E, K.
• Abnormal metabolism of vitamin D chronic renal
  failure.

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Rickets Non renal causes

• Nutritional
• Intestinal malabsorption
• Hepatobiliary
• Metabolic anticonvulsant therapy
• Rickets of prematurity

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Renal causes
Renal osteodystrophyCRFFamilial
hypophosphataemic ricketsRenal tubular
acidosisFanconi syndrome
Primary Secondary - cystinosis,
wilsons disease,lowe
syndrome,tyrosinemia


Vitamin D dependent type 1
ricketsVitamin D dependent type 2 rickets

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RicketsEffect at growth end plate

• Inadequate growth plate mineralization.
• Defective calcification in the interstitial
  regions
• The growth plate increases in thickness.
• The columns of cartilage cells are disorganized.

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Rickets

• Cupping of the epiphyses.
• Bones incapable of
• withstanding mechanical stresses
• and lead to bowing deformities.
• Eventual length of the long bones
• is diminished. ( short stature)

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Age of presentation

• VITAMIN D DEFICIENCY RICKETS
• 6 to 18 months.
• NON NUTRITIONAL RICKETS
• Beyond this age
  group.

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Skeletal manifestations of Rickets

• Craniotaes
• Delayed closure of anterior fontanelle
• Frontal and parietal bossing
• Delayed eruption of primary teeth
• Rosary

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Skeletal manifestations

• EXTREMITIES
• Enlargement of long bones around wrists and
  ankles
• Bow legs, knock knees
• green stick fractures

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Extra skeletal manifestations

• SEIZURES AND TETANY
• Secondary to hypocalcaemia
• HYPOTONIA AND DELAYED MOTOR DEVELOPMENT
  In rickets developing during infancy.

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Investigations,

• BASIC INVESTIGATIONS TO CONFIRM RICKETS
• Low or normal serum Ca
• Low phospherus
• High alkaline phosphatase
• X rays of ends of long bones at knees or wrists
• Shows Widening, fraying, cupping of the distal
  ends of shaft.
• Vit D level low
• Parathyroid hormone high

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Rickets

• Radiology changes

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Genu valgus
Tri radiate pelvis
Wrist widening
Wrist cupping
Loosers zones
Wide metaphysis
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Vitamin D Resistant Rickets

• In the renal tubular disorders, rickets
  develops in the presence of normal intestinal
  function and are not cured by normal doses of
  vitamin D.
• Resistant or refractory rickets.

Defective final conversion of Vit. D in to
active form or End organ insensitivity.
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Treatment of Rickets

• Vitamin D supplement
• Type and dose depends on underline cause of
  Rickets

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Causes of hypercalcaemia

• Hyperparathyroidism
• Vitamin D intoxicity
• William syndrome
• Familial hypocalcuric hypercalcaemia
• malignancy

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• Full term 1 year old boy who presented with
  afebrile tonic clonic convulsions. He has no
  chronic illnesses or medication. On examination
  he has no apparent dysmorphic features and his
  vital signs were normal.
• Describe an abnormality.
• List two important investigations to confirm your
  diagnosis.
• What is the most likely diagnosis?

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• Full term 1 year old boy who presented with
  afebrile tonic clonic convulsions. He has no
  chronic illnesses or medication. On examination
  he has no apparent dysmorphic features and his
  vital signs were normal.
• Describe an abnormality.
• List two other important investigations to
  confirm your diagnosis.

• Answer
• Bowing of legs
• 1. Serum calcium level, serum alkaline
  phosphatase, 25 Vitamin D level, hand x-ray
• 2. Possible diagnosis is nutritional Vitamin D
  deficiency.

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Data interpretation

• . An obese 2 year old girl was found to be
  hypocalcemic and did not respond to vitamin
  D.These results were found. Plasma Calcuim 1.2
  mmol/L , Plasma phosphate 2.8mmol/L ( N- 0.8-1.4)
• Alkaline Phosphatase 300 1u/L
• Urea 4mmol/L
• Magnesium 0.7 mmol/L
• Parathyroid hormone 20mg/ml ( n lt1)
• What is the most likely diagnosis? what may
  radiological exams of hand reveal?

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• An 8 ½ yr old girl followed by the Endocrine
  Clinic was apparently well until three years ago
  when she started to have muscle pains and
  difficulty in getting out of bed in the morning.
• Describe two abnormalities.
• Give the most likely diagnosis.

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• An 8 ½ yr old girl followed by the Endocrine
  Clinic was apparently well until three years ago
  when she started to have muscle pains and
  difficulty in getting out of bed in the morning.
• Describe two abnormalities.
• Give the most likely diagnosis.

• Answer
• Short stature bony deformity in the form of
  bowing of legs
• X-Linked Hypophosphatemic Rickets

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Thank you !