Diagnostic Pitfalls of a Newborn with Congenital Nephrogenic Diabetes Insipidus

Congenital nephrogenic diabetes insipidus (NDI) is a rare cause of hypernatremia in newborns. Central diabetes insipidus (CDI) is the main differential diagnosis of NDI. NDI responds poorly to desmopressin acetate (DDAVP) treatment while this is the mainstay of CDI management. Therefore, an early and correct diagnosis of NDI is crucial to avoid the complications of inappropriate therapy. Here, we report a newborn with hypernatremia and hypotonic polyuria. The patient was initially responsive but subsequently unresponsive to intranasal DDAVP treatment in regard to urine output and serum sodium levels. A novel hemizygous missense mutation (c.632T>C, p.L211P) in the AVPR2 gene was found both in the baby and his mother, and the diagnosis of congenital NDI was established. After hydrochlorothiazide treatment and hypo-osmolar formula were given, urine volume was decreased, and serum sodium levels were normalized. Early recognition and appropriate management of NDI can prevent complications of hypernatremic dehydration in young infants.

Vitamin D Deficiency Prevalence in Late Neonatal Hypocalcemia: A Multicenter Study

OBJECTIVE

Late neonatal hypocalcemia (LNH) is a common metabolic problem associated with hypoparathyroidism, high phosphate intake and vitamin D deficiency, often presenting with seizures. In this cross-sectional study, we aimed to evaluate the role of vitamin D deficiency in LNH in Turkey and to describe the characteristics of affected newborns.

METHODS

Conducted with a cross-sectional design and with the participation of 61 neonatal centers from December 2015 to December 2016, the study included term neonates with LNH (n=96) and their mothers (n=93). Data were registered on the FAVOR Web Registry System. Serum samples of newborns and mothers were analyzed for calcium, phosphate, magnesium, albumin, alkaline phosphatase, intact parathyroid hormone (iPTH) and 25 hydroxyvitamin D [25(OH)D] levels.

RESULTS

The median (range) onset time of hypocalcemia was 5.0 (4.0-8.0) days of age, with a male preponderance (60.4%). The median (range) serum 25(OH)D levels of the neonates and their mothers were 6.3 (4.1-9.05) and 5.2 (4.7-8.8) ng/mL, respectively. The prevalence of vitamin D deficiency (<12 ng/mL) was high in both the neonates (86.5%) and mothers (93%). Serum 25(OH)D levels of the infants and mothers showed a strong correlation (p<0.001). While the majority (93.7%) of the neonates had normal/high phosphorus levels, iPTH levels were low or inappropriately normal in 54.2% of the patients.

CONCLUSION

Vitamin D deficiency prevalence was found to be high in LNH. Efforts to provide vitamin D supplementation during pregnancy should be encouraged. Evaluation of vitamin D status should be included in the workup of LNH.

The long-term impacts of preterm birth and associated morbidities on bone health in preschool children: a prospective cross-sectional study from Turkey

Objective: To evaluate the impact of preterm birth on bone health in preschool children.Methods: A total of 166 preschool children (aged 7-8 years) born preterm (n = 86, <37-week gestation) and at term (n = 80, ≥37 weeks of gestation) in our hospital were included in this prospective cross-sectional study. Data on antenatal, perinatal, and early postnatal characteristics and maternal obstetric history were obtained from medical records. Bone densitometry data including total bone mineral content (BMC), bone mineral density (BMD; total, lumbar, and femoral), z-scores, and bone loss were collected for each participant.Results: Current height, weight, and BMI values were significantly lower in the preterm group (p < .001). Serum calcium, phosphorus and alkaline phosphatase (ALP) levels did not differ among groups, whereas VitD3 levels were significantly higher in the preterm group (p = .039). The mean total BMC, total BMD, lumbar (L2-L4) BMD, femur BMD, total z-score, and L2-L4 z-score values were significantly lower for the preterm group, whereas the total, lumbar, and femoral bone loss were significantly higher (p < .001), regardless of the severity of prematurity. Intraventricular hemorrhage (IVH) and retinopathy were significantly associated with lower total BMC (p = .004, p = .012, respectively). Fortified breastfeeding was associated with lumbar bone loss (p = .043), and formula feeding was associated with both femur and lumbar bone loss (p = .006, p = .012, respectively).Conclusions: Our findings revealed long-term adverse effects of preterm birth on bone health, with significantly lower anthropometric values (weight, height, and BMI), lower scores for total BMC, BMD (total, lumbar, femoral), and z-scores (total, femur), along with higher bone loss (total, lumbar, femoral) and higher rates of osteopenia and osteoporosis in preschool children born preterm (whether moderate or very preterm) compared with those born at term. Exclusive breastfeeding appears to reduce the likelihood of long-term bone loss in preterm infants.

A giant ovarian cyst in a neonate with classical 21-hydroxylase deficiency with very high testosterone levels demonstrating a high-dose hook effect

Congenital adrenal hyperplasia (CAH) is a group of disorders affecting the adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency (21-OHD), leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH, glucocorticoid treatment can be life-saving and serves to bring the symptoms under control. However, the treatment challenge is to effectively control the excess androgen effect by using the lowest possible glucocorticoid dose. Previous studies suggested a relationship between ovarian cyst formation and adrenal androgen excess, but neonatal large ovarian cysts have been very rarely reported in newborns with CAH. Here, we present the unique case of a neonate with classical 21-OHD who underwent surgery for a giant (10x8x7 cm) unilateral solitary ovarian follicular cyst on the 2nd postnatal day. Hormonal evaluation of the patient revealed high-dose hook effect for serum testosterone levels for the first time by a two-site immunoradiometric assay. Possible mechanisms by which androgen excess may cause ovarian cyst formation are discussed.

Critical points in the management of pseudohypoaldosteronism type 1

Pseudohypoaldosteronism type 1 (PHA-1, MIM #264350) is caused by defective transepithelial sodium transport. Affected patients develop life-threatening neonatal-onset salt loss, hyperkalemia, acidosis, and elevated aldosterone levels due to end-organ resistance to aldosterone. In this report, we present a patient diagnosed as PHA-1 who had clinical and laboratory findings compatible with the diagnosis and had genetically proven autosomal recessive PHA-1. The patient received high doses of sodium supplementation and potassium-lowering therapies; however, several difficulties were encountered in the management of this case. The aim of this presentation was to point out the potential pitfalls in the treatment of such patients in the clinical practice and to recommend solutions.