Kutilek S, Vracovska M, Pecenkova K, Brozikova H, Rondzikova E, Boskova E, Pikner R, Fejfarkova Z. Three cases of transient neonatal pseudohypoparathyroidism.
Sudan J Paediatr 2019;
18:42-47. [PMID:
30799898 DOI:
10.24911/sjp.106-1516889879]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neonatal hypocalcemia is defined as serum calcium (S-Ca) < 2.0 mmol/l in full-term newborns and <1.75 mmol/l in preterm newborns. Neonatal hypocalcemia is either early onset (<3 days of age) or late onset (>3 days of age). Newborns with hypocalcemia are often asymptomatic but may present with hypotonia, apnea, poor feeding, jitteriness, seizures, and cardiac failure. Signs of hypocalcemia rarely occur unless S-Ca drops below 1.75 mmol/l. Neonatal hypocalcemia can be a result of hypoparathyroidism (transient or primary), increased serum calcitonin, sepsis, asphyxia, hepatopathy, hypomagnesemia, high phosphate load, transient hypoparathyroidism, and, rarely, transient neonatal pseudohypoparathyroidism [transient resistance to biological actions of parathyroid hormone (PTH)]. We present the case of three boys (two with gestational age 39 weeks, one 36 weeks; none of them with either asphyxia or sepsis) with mild hypotonia, where S-Ca in the range of 1.67-1.9 mmol/l was detected within the first 3 days of life, together with hyperphosphatemia [serum phosphate (P) 2.5-2.6 mmol/l], normomagnesemia [serum magnesium (S-Mg) 0.77-0.88 mmol/l], normal alkaline phosphatase (ALP) activity (2.8-4.5 μkat/l), and high serum PTH (40-51 pg/ml; normal = 5-28). In spite of the gradual increase of S-Ca, the elevated serum PTH persisted beyond days 3, 4, and 6 in all three boys, together with normal or low-to-normal S-Ca, high or normal-to-high serum P, and no increases in serum ALP. The mothers S-Ca, P, Mg, ALP, and PTH levels were within normal reference ranges. With regard to laboratory results, the diagnosis of transient neonatal pseudohypoparathyroidism (due to immaturity of PTH-receptors) is highly probable in these three neonates.
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