2021
Novel homozygous variant in BMP1 associated with a rare osteogenesis imperfecta phenotype
Choksi I, Cox A, Robinson C, Bale A, Carpenter T. Novel homozygous variant in BMP1 associated with a rare osteogenesis imperfecta phenotype. Osteoporosis International 2021, 32: 1239-1244. PMID: 33624138, DOI: 10.1007/s00198-021-05838-1.Peer-Reviewed Original ResearchConceptsVertebral compression fracturesNovel homozygous variantOsteogenesis imperfectaMultiple vertebral compression fracturesZ-scoreHomozygous variantBilateral tibial fracturesLumbar spine BMDTotal hip BMDEffectiveness of bisphosphonatesFemoral neck BMDHeight z-scoreHomozygous missense variantBroad phenotypic spectrumBisphosphonate therapyBP therapySpinal osteopeniaSymptomatic reliefClinical presentationRecurrent fracturesSpine BMDTibial fracturesCompression fracturesHip BMDNeck BMD
2020
Long-Term Follow-up of Hypophosphatemic Bone Disease Associated With Elemental Formula Use: Sustained Correction of Bone Disease After Formula Change or Phosphate Supplementation
Eswarakumar AS, S. N, Ward LM, Backeljauw P, Wasserman H, Weber DR, DiMeglio LA, Imel EA, Gagne J, Cody D, Zimakas P, Topor LS, Agrawal S, Calabria A, Tebben P, Faircloth RS, Gordon R, Casey L, Carpenter TO. Long-Term Follow-up of Hypophosphatemic Bone Disease Associated With Elemental Formula Use: Sustained Correction of Bone Disease After Formula Change or Phosphate Supplementation. Clinical Pediatrics 2020, 59: 1080-1085. PMID: 32666808, DOI: 10.1177/0009922820941097.Peer-Reviewed Original ResearchConceptsElemental formula useBone diseaseFormula useHypophosphatemic bone diseaseTerm Follow-upLong-term outcomesSerum phosphorus concentrationSerum alkaline phosphatase activitySerum alkaline phosphataseSeverity/durationTime of correctionChart reviewSerum phosphorusDisease AssociatedFollow-upPhosphate supplementationExtent of recoveryDiseaseDiagnosisFormula changesRadiology reportsSupplementationAlkaline phosphataseAlkaline phosphatase activityReportEffects of Iron Isomaltoside vs Ferric Carboxymaltose on Hypophosphatemia in Iron-Deficiency Anemia
Wolf M, Rubin J, Achebe M, Econs MJ, Peacock M, Imel EA, Thomsen LL, Carpenter TO, Weber T, Brandenburg V, Zoller H. Effects of Iron Isomaltoside vs Ferric Carboxymaltose on Hypophosphatemia in Iron-Deficiency Anemia. JAMA 2020, 323: 432-443. PMID: 32016310, PMCID: PMC7042864, DOI: 10.1001/jama.2019.22450.Peer-Reviewed Original ResearchConceptsIron deficiency anemiaFerric carboxymaltoseIncidence of hypophosphatemiaIron isomaltosideDay 0Oral ironBone homeostasisCommon adverse drug reactionsFibroblast growth factor 23Trial ABiomarkers of mineralIntravenous iron isomaltosideRisk of hypophosphatemiaPrimary end pointReduced kidney functionGrowth factor 23Adverse drug reactionsIntravenous ironSerum phosphateFactor 23Kidney functionParathyroid hormoneRandomized trialsClinic sitesDrug reactions
2019
Relationship of Total and Free 25-Hydroxyvitamin D to Biomarkers and Metabolic Indices in Healthy Children
Simpson CA, Zhang JH, Vanderschueren D, Fu L, Pennestri TC, Bouillon R, Cole DEC, Carpenter TO. Relationship of Total and Free 25-Hydroxyvitamin D to Biomarkers and Metabolic Indices in Healthy Children. The Journal Of Clinical Endocrinology & Metabolism 2019, 105: dgz230. PMID: 31774125, PMCID: PMC7174047, DOI: 10.1210/clinem/dgz230.Peer-Reviewed Original ResearchConceptsBody mass indexVitamin D statusParathyroid hormoneUrban-dwelling childrenD statusGC haplotypeHomeostatic model assessmentSystolic blood pressureAcademic medical centerHeathy childrenBlood pressureClinical outcomesMass indexInsulin resistanceHealthy childrenMedical CenterMetabolic indicesModel assessmentRegistration noOutcome variablesHispanic backgroundChildrenStrongest correlateInsulinAvailable assessmentsSeverity of reduced bone mineral density and risk of fractures in long‐term survivors of childhood leukemia and lymphoma undergoing guideline‐recommended surveillance for bone health
Bloomhardt HM, Sint K, Ross WL, Rotatori J, Ness K, Robinson C, Carpenter TO, Chow EJ, Kadan‐Lottick N. Severity of reduced bone mineral density and risk of fractures in long‐term survivors of childhood leukemia and lymphoma undergoing guideline‐recommended surveillance for bone health. Cancer 2019, 126: 202-210. PMID: 31536650, DOI: 10.1002/cncr.32512.Peer-Reviewed Original ResearchConceptsLow bone mineral densityReduced bone mineral densityBone mineral densityLymphoma survivorsMineral densityLumbar spine BMD Z-scoreChildhood leukemia/lymphomaPatient/treatment factorsSpine BMD Z-scoreDual-energy X-ray absorptiometryGuideline-recommended surveillanceBMD Z-scoresLong-term survivorsRisk of fractureCross-sectional studyLeukemia/lymphomaLong bone fracturesX-ray absorptiometrySurvivorship clinicBone healthMultivariable analysisMean ageChronic conditionsMedical recordsWhite raceContinued Beneficial Effects of Burosumab in Adults with X-Linked Hypophosphatemia: Results from a 24-Week Treatment Continuation Period After a 24-Week Double-Blind Placebo-Controlled Period
Portale AA, Carpenter TO, Brandi ML, Briot K, Cheong HI, Cohen-Solal M, Crowley R, Jan De Beur S, Eastell R, Imanishi Y, Imel EA, Ing S, Ito N, Javaid M, Kamenicky P, Keen R, Kubota T, Lachmann R, Perwad F, Pitukcheewanont P, Ralston SH, Takeuchi Y, Tanaka H, Weber TJ, Yoo HW, Zhang L, Theodore-Oklota C, Mealiffe M, San Martin J, Insogna K. Continued Beneficial Effects of Burosumab in Adults with X-Linked Hypophosphatemia: Results from a 24-Week Treatment Continuation Period After a 24-Week Double-Blind Placebo-Controlled Period. Calcified Tissue International 2019, 105: 271-284. PMID: 31165191, DOI: 10.1007/s00223-019-00568-3.Peer-Reviewed Original ResearchConceptsWeek 48Adverse eventsWeek 24Sustained improvementTreatment-related serious adverse eventsOpen-label treatment periodSafety of burosumabDouble-blind placeboFatal adverse eventsSerious adverse eventsSerum phosphorus levelsPatient-reported outcomesSerum phosphorus concentrationRenal phosphate wastingHuman monoclonal antibodyContinued beneficial effectsHealing of fracturesRare genetic disorderMusculoskeletal morbidityPhysical functionContinuation periodMusculoskeletal impairmentsPhosphate wastingTreatment periodBurosumabEfficacy and safety of burosumab in children aged 1–4 years with X-linked hypophosphataemia: a multicentre, open-label, phase 2 trial
Whyte MP, Carpenter TO, Gottesman GS, Mao M, Skrinar A, San Martin J, Imel EA. Efficacy and safety of burosumab in children aged 1–4 years with X-linked hypophosphataemia: a multicentre, open-label, phase 2 trial. The Lancet Diabetes & Endocrinology 2019, 7: 189-199. PMID: 30638856, DOI: 10.1016/s2213-8587(18)30338-3.Peer-Reviewed Original ResearchConceptsSerum phosphorus concentrationPhase 2 trialWeeks of treatmentAdverse eventsWeek 40Week 64Serum phosphorusPhosphatonin fibroblast growth factor 23Treatment-related adverse eventsFibroblast growth factor 23History of toothRickets Severity ScoreSafety of burosumabSerious adverse eventsInjection site reactionsKey secondary outcomesFavorable safety profileGrowth factor 23Severe food allergyHeight z-scoreKey inclusion criteriaRenal phosphate wastingHuman monoclonal antibodyRadiographic Global ImpressionYoung children
2018
A Randomized, Double‐Blind, Placebo‐Controlled, Phase 3 Trial Evaluating the Efficacy of Burosumab, an Anti‐FGF23 Antibody, in Adults With X‐Linked Hypophosphatemia: Week 24 Primary Analysis
Insogna KL, Briot K, Imel EA, Kamenický P, Ruppe MD, Portale AA, Weber T, Pitukcheewanont P, Cheong HI, de Beur S, Imanishi Y, Ito N, Lachmann RH, Tanaka H, Perwad F, Zhang L, Chen C, Theodore‐Oklota C, Mealiffe M, San Martin J, Carpenter TO, Investigators O. A Randomized, Double‐Blind, Placebo‐Controlled, Phase 3 Trial Evaluating the Efficacy of Burosumab, an Anti‐FGF23 Antibody, in Adults With X‐Linked Hypophosphatemia: Week 24 Primary Analysis. Journal Of Bone And Mineral Research 2018, 33: 1383-1393. PMID: 29947083, DOI: 10.1002/jbmr.3475.Peer-Reviewed Original ResearchConceptsTreatment-related serious adverse eventsMean serum phosphate concentrationWOMAC physical function subscaleFibroblast growth factor 23Intact parathyroid hormoneSerious adverse eventsPhase 3 trialPhysical function subscaleChronic musculoskeletal painGrowth factor 23Serum phosphate concentrationRenal phosphate wastingHuman monoclonal antibodyLower limb deformitiesImportant medical needStiffness subscalePlacebo groupUrine calciumWorst painAdverse eventsWeek 24Dental abscessMusculoskeletal painFactor 23Function subscaleBurosumab Therapy in Children with X-Linked Hypophosphatemia
Carpenter TO, Whyte MP, Imel EA, Boot AM, Högler W, Linglart A, Padidela R, Van't Hoff W, Mao M, Chen CY, Skrinar A, Kakkis E, San Martin J, Portale AA. Burosumab Therapy in Children with X-Linked Hypophosphatemia. New England Journal Of Medicine 2018, 378: 1987-1998. PMID: 29791829, DOI: 10.1056/nejmoa1714641.Peer-Reviewed Original ResearchMeSH KeywordsAlkaline PhosphataseAntibodies, MonoclonalAntibodies, Monoclonal, HumanizedChildChild, PreschoolFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsGenetic Diseases, X-LinkedGrowthHumansKidney TubulesKnee JointMalePain ManagementPhosphorusRadiographySeverity of Illness IndexConceptsSerum phosphorus levelsRenal tubular phosphate reabsorptionTubular phosphate reabsorptionWeek 40Week 64Adverse eventsPhosphate reabsorptionNormal rangeMean serum phosphorus levelFibroblast growth factor 23End pointMean serum alkaline phosphatase levelSerum alkaline phosphatase levelsTotal scorePrimary end pointPhase 2 trialGrowth factor 23Additional end pointsPatient-reported outcomesAlkaline phosphatase levelsRadiographic Global ImpressionPhosphorus levelsOverall mean increaseBurosumab therapySubcutaneous burosumabThree-Month Randomized Clinical Trial of Nasal Calcitonin in Adults with X-linked Hypophosphatemia
Sullivan R, Abraham A, Simpson C, Olear E, Carpenter T, Deng Y, Chen C, Insogna KL. Three-Month Randomized Clinical Trial of Nasal Calcitonin in Adults with X-linked Hypophosphatemia. Calcified Tissue International 2018, 102: 666-670. PMID: 29383408, PMCID: PMC5957766, DOI: 10.1007/s00223-017-0382-0.Peer-Reviewed Original ResearchConceptsLevels of FGF23Nasal salmon calcitoninSalmon calcitoninStudy drugVisit 2Day 2Levels of PTHPrincipal outcome variableTmP/GFRSingle subcutaneous dosePlacebo nasal sprayNasal calcitoninSerum calciumSubcutaneous doseVisit 4Dihydroxyvitamin DSerum phosphorusVisit 3Final doseVisit 1Nasal sprayClinical trialsSerial measurementsDrug doseFGF23 production
2017
Unexpected widespread hypophosphatemia and bone disease associated with elemental formula use in infants and children
Ballesteros L, S. N, Gordon RJ, Ward L, Backeljauw P, Wasserman H, Weber DR, DiMeglio LA, Gagne J, Stein R, Cody D, Simmons K, Zimakas P, Topor LS, Agrawal S, Calabria A, Tebben P, Faircloth R, Imel EA, Casey L, Carpenter TO. Unexpected widespread hypophosphatemia and bone disease associated with elemental formula use in infants and children. Bone 2017, 97: 287-292. PMID: 28167344, PMCID: PMC5884631, DOI: 10.1016/j.bone.2017.02.003.Peer-Reviewed Original ResearchConceptsElemental formula useFormula useSkeletal diseaseRetrospective chart reviewInadequate dietary intakeCertain clinical settingsFormula productsEffect of treatmentSevere malabsorptionChart reviewSevere hypocalcemiaClinical featuresClinical profileRenal excretionDietary intakeCommon findingMineral metabolismBone diseaseHypophosphatemiaPhosphate supplementationSkeletal radiographsCareful monitoringComplex illnessRenal conservationClinical setting
2016
Hypophosphatemia promotes lower rates of muscle ATP synthesis
Pesta DH, Tsirigotis DN, Befroy DE, Caballero D, Jurczak MJ, Rahimi Y, Cline GW, Dufour S, Birkenfeld AL, Rothman DL, Carpenter TO, Insogna K, Petersen KF, Bergwitz C, Shulman GI. Hypophosphatemia promotes lower rates of muscle ATP synthesis. The FASEB Journal 2016, 30: 3378-3387. PMID: 27338702, PMCID: PMC5024687, DOI: 10.1096/fj.201600473r.Peer-Reviewed Original ResearchConceptsMuscle ATP synthesisATP synthesisMuscle weaknessIsolated muscle mitochondriaSolute carrier familyWild-type littermate controlsSolute carrier family 34Carrier familyLower ratesInsulin-stimulated ratesMuscle mitochondriaChronic hypophosphatemiaHeart failureHypophosphatemic groupHypophosphatemic miceHypophosphatemiaLittermate controlsKnockout miceBlood PLow ratePlasma PPatientsSimilar findingsMember 1Plasma inorganic phosphate
2015
Conventional Therapy in Adults With X-Linked Hypophosphatemia: Effects on Enthesopathy and Dental Disease
Connor J, Olear EA, Insogna KL, Katz L, Baker S, Kaur R, Simpson CA, Sterpka J, Dubrow R, Zhang JH, Carpenter TO. Conventional Therapy in Adults With X-Linked Hypophosphatemia: Effects on Enthesopathy and Dental Disease. The Journal Of Clinical Endocrinology & Metabolism 2015, 100: 3625-3632. PMID: 26176801, PMCID: PMC4596038, DOI: 10.1210/jc.2015-2199.Peer-Reviewed Original ResearchConceptsSevere dental diseaseHospital research unitDental diseaseDisease severityXLH patientsMajor long-term morbidityActive vitamin D metaboliteAdult XLH patientsLong-term morbidityVitamin D metabolitesAdult lifeMultiple logistic regressionRadiographic skeletal surveySignificant predictorsProportion of adultsConventional therapyD metabolitesSkeletal surveyLower riskExposure variablesLogistic regressionDiseaseEnthesopathySkeletal deformitiesTreatment variablesProlonged Correction of Serum Phosphorus in Adults With X-Linked Hypophosphatemia Using Monthly Doses of KRN23
Imel EA, Zhang X, Ruppe MD, Weber TJ, Klausner MA, Ito T, Vergeire M, Humphrey JS, Glorieux FH, Portale AA, Insogna K, Peacock M, Carpenter TO. Prolonged Correction of Serum Phosphorus in Adults With X-Linked Hypophosphatemia Using Monthly Doses of KRN23. The Journal Of Clinical Endocrinology & Metabolism 2015, 100: 2565-2573. PMID: 25919461, PMCID: PMC4495171, DOI: 10.1210/jc.2015-1551.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAntibodies, MonoclonalAntibodies, Monoclonal, HumanizedDose-Response Relationship, DrugDrug Administration ScheduleFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsGlomerular Filtration RateHumansImmunoglobulin GMaleMiddle AgedPhosphorusRecombinant ProteinsTreatment OutcomeYoung AdultConceptsTmP/GFRSerum PiNormal rangeOpen-label phase 1/2 studyElevated fibroblast growth factor 23Fibroblast growth factor 23Phase 1/2 studyDose-escalation studyGlomerular filtration ratePre-dose levelsGrowth factor 23Favorable safety profileMain outcome measuresProportion of subjectsAcademic medical centerPeak PiSerum inorganic phosphorusPg/mLUrinary calciumDose escalationFactor 23Monthly dosesSerum phosphorusDihydroxyvitamin DSafety profileAssociation between serum 25‐hydroxyvitamin D level and pulmonary exacerbations in cystic fibrosis
Vanstone MB, Egan ME, Zhang JH, Carpenter TO. Association between serum 25‐hydroxyvitamin D level and pulmonary exacerbations in cystic fibrosis. Pediatric Pulmonology 2015, 50: 441-446. PMID: 25657016, DOI: 10.1002/ppul.23161.Peer-Reviewed Original ResearchConceptsPulmonary function testsCystic fibrosisPulmonary exacerbationsPediatric patientsD levelsYale-New Haven HospitalPediatric CF patientsVitamin D sufficiencyRetrospective chart reviewVitamin D statusStrongest independent determinantCF care centersPatients ages 5Logistic regression analysisAnnual numberD sufficiencyD statusChart reviewClinic visitsLung functionPulmonary functionAntibiotic therapyFunction testsHospitalization ratesIndependent determinants
2014
Effect of Paricalcitol on Circulating Parathyroid Hormone in X-Linked Hypophosphatemia: A Randomized, Double-Blind, Placebo-Controlled Study
Carpenter TO, Olear EA, Zhang JH, Ellis BK, Simpson CA, Cheng D, Gundberg CM, Insogna KL. Effect of Paricalcitol on Circulating Parathyroid Hormone in X-Linked Hypophosphatemia: A Randomized, Double-Blind, Placebo-Controlled Study. The Journal Of Clinical Endocrinology & Metabolism 2014, 99: 3103-3111. PMID: 25029424, PMCID: PMC4154090, DOI: 10.1210/jc.2014-2017.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAlkaline PhosphataseBone Density Conservation AgentsChildDouble-Blind MethodErgocalciferolsFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsHumansHyperparathyroidismMaleMiddle AgedParathyroid HormonePhosphorusPlacebosProspective StudiesTreatment OutcomeVitamin DYoung AdultConceptsRenal phosphate thresholdGlomerular filtration rateBone scanSerum phosphorusFiltration rateXLH patientsEffect of paricalcitolUse of paricalcitolPlacebo-treated subjectsElevated PTH levelsSerum calcium levelsSuppression of PTHHospital research unitSerum alkaline phosphatase activityPTH levelsCreatinine levelsSecondary outcomesStandard therapyUrinary calciumPlacebo subjectsParathyroid hormoneSerum calciumAlkaline phosphatase activityD levelsSkeletal improvementMutations in SLC34A3/NPT2c Are Associated with Kidney Stones and Nephrocalcinosis
Dasgupta D, Wee MJ, Reyes M, Li Y, Simm PJ, Sharma A, Schlingmann KP, Janner M, Biggin A, Lazier J, Gessner M, Chrysis D, Tuchman S, Baluarte HJ, Levine MA, Tiosano D, Insogna K, Hanley DA, Carpenter TO, Ichikawa S, Hoppe B, Konrad M, Sävendahl L, Munns CF, Lee H, Jüppner H, Bergwitz C. Mutations in SLC34A3/NPT2c Are Associated with Kidney Stones and Nephrocalcinosis. Journal Of The American Society Of Nephrology 2014, 25: 2366-2375. PMID: 24700880, PMCID: PMC4178443, DOI: 10.1681/asn.2013101085.Peer-Reviewed Original ResearchConceptsIdiopathic hypercalciuriaDecreased tubular reabsorption of phosphateIncreased risk of kidney stone formationSerum 1,25(OH)2 vitamin DTubular reabsorption of phosphateAssociated with kidney stonesVitamin D levelsSolute carrier family 34Renal phosphate wastingDecreased serum phosphateHereditary hypophosphatemic ricketsHealthy family membersReabsorption of phosphateRisk of kidney stone formationRickets/osteomalaciaDecreased tubular reabsorptionKidney stone formationSLC34A3 mutationsIndependent of genotypeMedullary nephrocalcinosisSerum phosphateVitamin DDependent phosphate cotransporterTubular reabsorptionD levelsRandomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia
Carpenter TO, Imel EA, Ruppe MD, Weber TJ, Klausner MA, Wooddell MM, Kawakami T, Ito T, Zhang X, Humphrey J, Insogna KL, Peacock M. Randomized trial of the anti-FGF23 antibody KRN23 in X-linked hypophosphatemia. Journal Of Clinical Investigation 2014, 124: 1587-1597. PMID: 24569459, PMCID: PMC3973088, DOI: 10.1172/jci72829.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAntibodies, MonoclonalAntibodies, Monoclonal, HumanizedCalciumFamilial Hypophosphatemic RicketsFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsGlomerular Filtration RateHalf-LifeHumansInjections, IntravenousInjections, SubcutaneousKidney TubulesMaleMiddle AgedPhosphatesVitamin DYoung AdultConceptsTmP/GFRSerum PiParathyroid hormonePhosphate reabsorptionXLH patientsRenal tubular thresholdSerum parathyroid hormoneFavorable safety profileElevated serum FGF23Renal phosphate reabsorptionLow serum concentrationsPhosphate-regulating endopeptidaseSerum Pi concentrationFGF23 antibodySerum FGF23Dihydroxyvitamin DSafety profileTubular thresholdSingle doseSerum concentrationsKRN23Mean t1/2Potential treatmentPatientsEffect durationGastric bypass in obese rats causes bone loss, vitamin D deficiency, metabolic acidosis, and elevated peptide YY
Canales BK, Schafer AL, Shoback DM, Carpenter TO. Gastric bypass in obese rats causes bone loss, vitamin D deficiency, metabolic acidosis, and elevated peptide YY. Surgery For Obesity And Related Diseases 2014, 10: 878-884. PMID: 24969093, PMCID: PMC4113565, DOI: 10.1016/j.soard.2014.01.021.Peer-Reviewed Original ResearchConceptsBone turnover markersDiet-induced obeseWeeks of ageSham surgeryBone lossPeptide YYRYGB animalsBone volumeHigher serum parathyroid hormoneLower trabecular bone volumeMale Sprague-Dawley ratsBone mass differencesElevated peptide YYHigher serum CTXVitamin D malabsorptionSerum parathyroid hormoneGastric bypass surgeryLow serum bicarbonateVitamin D deficiencyNormal calcium dietCortical bone volumeSham control ratsTrabecular bone volumeSprague-Dawley ratsMetabolic bone disease
2013
Exome sequencing reveals FAM20c mutations associated with fibroblast growth factor 23–related hypophosphatemia, dental anomalies, and ectopic calcification
Rafaelsen SH, Ræder H, Fagerheim AK, Knappskog P, Carpenter TO, Johansson S, Bjerknes R. Exome sequencing reveals FAM20c mutations associated with fibroblast growth factor 23–related hypophosphatemia, dental anomalies, and ectopic calcification. Journal Of Bone And Mineral Research 2013, 28: 1378-1385. PMID: 23325605, DOI: 10.1002/jbmr.1850.Peer-Reviewed Original ResearchConceptsFibroblast growth factor 23Growth factor 23Factor 23Dental anomaliesExome sequencingAbsence of ricketsFAM20C mutationsCompound heterozygous mutationsWhole-exome sequencingIntracerebral calcificationsFGF23 levelsFamilial hypophosphatemiaHypophosphatemic ricketsEctopic calcificationHypophosphatemiaPutative new mechanismsType 1Heterozygous mutationsUndiagnosed probandsLong bonesNorwegian populationCausal roleHuman subjectsSequence similarity 20Rickets