Aromatase deficiency in a tall man: Case report of two novel mutations and review of literature

Aromatase (CYP19A1) is the only enzyme known to catalyse the conversion of androgen to estrogen. Aromatase deficiency occurs due to mutation in CYP19A1gene which has an autosomal recessive inheritance pattern. It leads to decrease in estrogen synthesis and delayed epiphyseal closure, eunuchoid habitus and osteopenia. We are presenting here, a 24 years old male, with history of progressive increase in height and knock knees. X-ray showed open wrist and knee epiphysis. The serum testosterone level was normal and serum estradiol level was undetectable. Semen analysis showed azoospermia. Clinical exome sequencing gave two novel mutations in CYP19A1. The first variant was a novel single nucleotide deletion of thiamine at 570th base of the cDNA (c.570delT) of CYP19A1 gene. The second variant detected was again a novel one in the same gene in Exon 5 corresponding 344th base of the cDNA (c344G>A) resulting in a missense mutation of 115th arginine to glutamine in the protein. Sanger sequencing showed that the later mutation was inherited from the father. The patient was started on oral estradiol valerate for epiphyseal closure to prevent further increase in height. Only 15 mutations have been reported in the aromatase gene in males till date, our report of these novel mutations will be an add-on to the literature.

High-dose vitamin D supplementation in pregnancy and 25(OH)D sufficiency in childhood reduce the risk of fractures and improve bone mineralization in childhood: Follow-up of a randomized clinical trial

BACKGROUND

Exposure to vitamin D in early life has been associated with improved bone mineralization, but no studies have investigated the combined effect of pregnancy supplementation and childhood 25(OH)D concentrations on bone health.

METHODS

We analyzed the effect of serum 25(OH)D concentrations at age 6 months and 6 years and the combined effect with prenatal high-dose vitamin D (2800 vs. 400 IU/day) on bone mineral density (BMD) and content (BMC) assessed by dual-energy X-ray absorptiometry (DXA) scans at age 3 and 6 years and longitudinal risk of fractures in a double-blinded, randomized clinical trial in the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC₂₀₁₀) mother-child cohort with enrollment from March 4, 2009, to November 17, 2010, and clinical follow-up until January 31, 2019 (NCT00856947). All participants randomized to intervention and with complete data were included in the analyses.

FINDINGS

At age 6 months, serum 25(OH)D concentration was measured in 93% (n = 541) of 584 children. Children with sufficient (≥ 75 nmol/l) vs. insufficient (< 75 nmol/l) concentrations did not have lower risk of fractures: incidence rate ratio (95% CI); 0.64 (0.37;1.11), p = 0.11. However, vitamin D sufficient children from mothers receiving high-dose supplementation during pregnancy had a 60% reduced incidence of fractures compared with vitamin D insufficient children from mothers receiving standard-dose: 0.40 (0.19;0.84), p = 0.02.At age 6 years, serum 25(OH)D concentration was measured in 83% (n = 318) of 383 children with available DXA data. Whole-body bone mineralization was higher in vitamin D sufficient children at age 6 years; BMD, adjusted mean difference (aMD) (95% CI): 0.011 g/cm² (0.001;0.021), p = 0.03, and BMC, aMD: 12.3 g (-0.8;25.4), p = 0.07, with the largest effect in vitamin D sufficient children from mothers receiving high-dose vitamin D supplementation; BMD, aMD: 0.016 g/cm² (0.002;0.030), p = 0.03, and BMC, aMD: 23.5 g (5.5;41.5), p = 0.01.

INTERPRETATION

Childhood vitamin D sufficiency improved bone mineralization and in combination with prenatal high-dose vitamin D supplementation reduced the risk of fractures.

FUNDING

The study was supported by The Lundbeck Foundation R16-A1694, The Danish Ministry of Health 903,516, The Danish Council for Strategic Research 0603-00280B and The European Research Council 946,228.

Severe injury-induced osteoporosis and skeletal muscle mineralization: Are these related complications?

Severely injured patients are beleaguered by complications during convalescence, such as dysregulated biomineralization. Paradoxically, severely injured patients experience the loss of bone (osteoporosis), resulting in diminished skeletal integrity and increased risk of fragility fractures; yet they also accrue mineralization in soft tissues, resulting in complications such as heterotopic ossification (HO). The pathophysiology leading to dysregulated biomineralization in severely injured patients is not well defined. It has been postulated that these pathologies are linked, such that mineralization is "transferred" from the bone to soft tissue compartments. The goal of this study was to determine if severe injury-induced osteoporosis and soft tissue calcification are temporally coincident following injury. Using a murine model of combined burn and skeletal muscle injury to model severe injury, it was determined that mice developed significant progressive bone loss, detectable as early as 3 days post injury, and marked soft tissue mineralization by 7 days after injury. The observed temporal concordance between the development of severe injury-induced osteoporosis and soft tissue mineralization indicates the plausibility that these complications share a common pathophysiology, though further experiments are required.

Effect of two prophylactic bolus vitamin D dosing regimens (1000 IU/day vs. 400 IU/day) on bone mineral content in new-onset and infrequently-relapsing nephrotic syndrome: a randomised clinical trial

OBJECTIVES

To examine the efficacy of two vitamin D dosages (1000 vs. 400 IU/day) for osteoprotection in children with new-onset and infrequently-relapsing nephrotic syndrome (IFRNS) receiving corticosteroids.

METHODS

This parallel-group, open label, randomised clinical trial enrolled 92 children with new-onset nephrotic syndrome (NS) (n = 28) or IFRNS (n = 64) to receive 1000 IU/day (Group A, n = 46) or 400 IU/day (Group B, n = 46) vitamin D (administered as a single bolus initial supplemental dose) by block randomisation in a 1:1 allocation ratio. In Group A, vitamin D (cholecalciferol in a Calcirol® sachet) was administered in a single stat dose of 84,000 IU on Day 1 of steroid therapy (for new-onset NS), calculated for a period of 12 weeks@1000 IU/day) and 42,000 IU on Day 1 of steroid therapy (for IFRNS, calculated for a period of 6 weeks@1000 IU/day). In Group B, vitamin D (cholecalciferol in a Calcirol® sachet) was administered as a single stat dose of 33,600 IU on Day 1 of steroid therapy (for new-onset NS, calculated for a period of 12 weeks@400 IU/day) and 16,800 IU on Day 1 of steroid therapy (for IFRNS, calculated for a period of 6 weeks@400 IU/day). The proportionate change in bone mineral content (BMC) was analysed in both groups after vitamin D supplementation.

RESULTS

Of the 92 children enrolled, 84 (n = 42 new onset, n = 42 IFRNS) completed the study and were included in the final analysis. Baseline characteristics including initial BMC, bone mineral density, cumulative prednisolone dosage and serum 25-hydroxycholecalciferol levels were comparable in the two groups. There was a greater median proportionate change in BMC in the children who received 1000 IU/day vitamin D (3.25%, IQR -1.2 to 12.4) than in those who received 400 IU/day vitamin D (1.2%, IQR -2.5 to 3.8, p = 0.048). The difference in proportionate change in BMC was only statistically significant in the combined new-onset and IFRNS, but not for IFRNS alone. There was a greater median proportionate change in serum 25-hydroxycholecalciferol, in the children who received 1000 IU/day vitamin D (20.6%, IQR 14.9-36.75) than in those who received 400 IU/day vitamin D (7.7%, IQR 3.5-18.5, p < 0.01). There was a greater median proportionate change in serum calcium in the children who received 1000 IU/day vitamin D (20%, IQR 13.1-29.0) than in those who received 400 IU/day vitamin D (11.3%, IQR 2.8-25.0, p = 0.03). Despite vitamin D therapy, BMC decreased from the baseline in 15 (32.6%) children receiving 1000 IU/day vitamin D and in 17 (36.9%) children receiving 400 IU/day vitamin D. There were no adverse effects attributable to vitamin D.

CONCLUSION

The 1000 IU/day dose is marginally more effective than 400 IU/day and it is likely than an even larger dose is required. Further research is required to assess the efficacy and safety of vitamin D doses higher than 1000 IU/day.

Bone mineral density in mucopolysaccharidosis IVB

To date, the only published reports of bone mineral density (BMD) in MPS IV involve patients with MPS IVA; no reports exist describing BMD for MPS IVB. In this prospective study of BMD in three patients with MPS IVB, BMD was acquired by dual-energy X-ray absorptiometry (DXA) at whole body (WB), lumbar spine (LS), and lateral distal femur (LDF). Functional abilities, ambulatory status, medical history, and height z-score were evaluated. Three patients with MPS IVB (two females), aged 17.7, 31.4 and 31.7 years, were evaluated. Every patient was ambulatory and one sustained two fractures caused by trauma. Whole body and hip DXA scans were technically invalid in every patient due to the presence of prosthetic hip hardware. Lumbar spine was valid in only 1 patient due skeletal abnormalities, and was normal (Z-score of − 0.8). The LDF was valid in every patient and was low at all three regions of interest: average LDF z-scores were − 3.1 (range, − 2.9 to − 3.6), − 2.3 (range, − 2.0 to − 2.5), and − 2.1 (range, − 2.0 to − 2.3) for region 1–region 3, respectively. Patients with MPS IVB have low BMD of the lower extremities even with full-time ambulation. Routine body sites to measure by DXA were problematic; hip and WB were invalid due to artifact, and LS had limited utility. The LDF was the only body site consistently available on all patients. Patients did not experience low-energy fractures despite low BMD.

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This is the first report of BMD in MPS IVB.

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Assessment of BMD in 3 patients with Morquio B is challenging using typical body sites measured by DXA.

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Hip replacements preclude proximal femur and whole body DXA; abnormal vertebral shape limits the use of lumbar spine DXA.

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The lateral distal femur DXA was obtainable and technically valid.

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Despite ambulation, lower extremity BMD was below normal.

Is bone equally responsive to calcium and vitamin D intake from food vs. supplements? Use of (41)calcium tracer kinetic model

Background

Few interventions directly compare equivalent calcium and vitamin D from dairy vs. supplements on the same bone outcomes. The radioisotope calcium-41 (⁴¹Ca) holds promise as a tracer method to directly measure changes in bone resorption with differing dietary interventions.

Objective

Using ⁴¹Ca tracer methodology, determine if 4 servings/day of dairy foods results in greater ⁴¹Ca retention than an equivalent amount of calcium and vitamin D from supplements. Secondary objective was to evaluate the time course for the change in ⁴¹Ca retention.

Methods

In this crossover trial, postmenopausal women (n = 12) were dosed orally with 100 nCi of ⁴¹Ca and after a 180 day equilibration period received dairy (4 servings/day of milk or yogurt; ~ 1300 mg calcium, 400 IU cholecalciferol (vitamin D₃/day)) or supplement treatments (1200 mg calcium carbonate/day and 400 IU vitamin D₃/day) in random order. Treatments lasted 6 weeks separated by a 6 week washout (WO). Calcium was extracted from weekly 24 h urine collections; accelerator mass spectrometry (AMS) was used to determine the ^41/40Ca ratio. Primary outcome was change in ^41/40Ca excretion. Secondary outcome was the time course for change in ⁴¹Ca excretion during intervention and WO periods.

Results

The ^41/40Ca ratio decreased significantly over time during both treatments; there was no difference between treatments. Both treatments demonstrated a significant retention of ⁴¹Ca within 1–2 weeks (p = 0.0007 and p < 0.001 for dairy and supplements, respectively). WO demonstrated a significant decrease (p = 0.0024) in ⁴¹Ca retention within 1–2 weeks, back to pre-intervention levels.

Conclusion

These data demonstrate that urinary ⁴¹Ca retention is increased with an increase in calcium and vitamin D intake regardless of the source of calcium, and the increased retention occurs within 1–2 weeks.

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Investigated, using ⁴¹Ca tracer, whether bone response to calcium and vitamin D differed based on the source of nutrients, foods vs. supplements.

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There was no difference in the bone response by treatment group.

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Both dairy foods and supplements resulted in reduce ⁴¹Ca excretion in urine.

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Reduction in ⁴¹Ca excretion occurred with 2 weeks of initiating the interventions.

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Removal of interventions resulted in 41Ca excretion returning to pre-intervention levels