A Novel Osteochondrodysplasia With Empty Sella Associates With a TBX2 Variant

Skeletal dysplasias comprise a heterogenous group of developmental disorders of skeletal and cartilaginous tissues. Several different forms have been described and the full spectrum of their clinical manifestations and underlying genetic causes are still incompletely understood. We report a three-generation Finnish family with an unusual, autosomal dominant form of osteochondrodysplasia and an empty sella. Affected individuals (age range 24-44 years) exhibit unusual codfish-shaped vertebrae, severe early-onset and debilitating osteoarthritis and an empty sella without endocrine abnormalities. Clinical characteristics also include mild dysmorphic features, reduced sitting height ratio, and obesity. Whole-exome sequencing excluded known skeletal dysplasias and identified a novel heterozygous missense mutation c.899C>T (p.Thr300Met) in TBX2, confirmed by Sanger sequencing. TBX2 is important for development of the skeleton and the brain and three prior reports have described variations in TBX2 in patients portraying a complex phenotype with vertebral anomalies, craniofacial dysmorphism and endocrine dysfunctions. Our mutation lies near a previously reported disease-causing variant and is predicted pathogenic with deleterious effects on protein function. Our findings expand the current spectrum of skeletal dysplasias, support the association of TBX2 mutations with skeletal dysplasia and suggest a role for TBX2 in development of the spinal and craniofacial structures and the pituitary gland.

A family with partially penetrant multicentric carpotarsal osteolysis due to gonadal mosaicism: First reported case

Multicentric carpotarsal osteolysis (MCTO) is an autosomal dominant condition characterized by carpal-tarsal abnormalities; over half of affected individuals also develop renal disease. MCTO is caused by mutations of MAFB; however, there is no clear phenotype-genotype correlation. We describe the first reported family of variable MCTO phenotype due to mosaicism: the proband had classical skeletal features and renal involvement due to focal segmental glomerulosclerosis (FSGS), and the father had profound renal impairment due to FSGS, necessitating kidney transplantation. Mosaicism was first suspected in this family due to unequal allele ratios in the sequencing chromatograph of the initial blood sample of proband's father and confirmed by sequencing DNA extracted from the father's hair, collected from different bodily parts. This case highlights the need for a high index of clinical suspicion to detect low-level parental mosaicism, as well as a potential role for MAFB mutation screening in individuals with isolated FSGS.

Pulmonary Follow-Up Imaging in Cartilage-Hair Hypoplasia: a Prospective Cohort Study

Cartilage-hair hypoplasia is a syndromic immunodeficiency with short stature, chondrodysplasia, and variable degree of immune dysfunction. Patients with cartilage-hair hypoplasia are prone to recurrent respiratory tract infections, and the prevalence of bronchiectasis ranges from 29 to 52%. Pulmonary complications contribute significantly to the mortality; therefore, regular lung imaging is essential. However, the optimal schedule for repeated lung imaging remains unestablished. We determined the rate and correlates of progression of structural lung changes in a prospectively followed cohort of 16 patients with cartilage-hair hypoplasia. We analyzed clinical, laboratory, and pulmonary functional testing data and performed lung magnetic resonance imaging at a median interval of 6.8 years since previous imaging. Imaging findings remained identical or improved due to disappearance of inflammatory changes in all evaluated patients. Patients with subtle signs of bronchiectasis on imaging tended to have low immunoglobulin M levels, as well as suffered from pneumonia during the follow-up. In conclusion, our results suggest slow if any development of bronchiectasis in selected subjects with cartilage-hair hypoplasia.

Towards multimodal brain monitoring in asphyxiated newborns with amplitude-integrated EEG and simultaneous somatosensory evoked potentials

BACKGROUND

Somatosensory evoked potentials (SEPs) offer an additional bedside tool for outcome prediction after perinatal asphyxia.

AIMS

To assess the reliability of SEPs recorded with bifrontoparietal amplitude-integrated electroencephalography (aEEG) brain monitoring setup for outcome prediction in asphyxiated newborns undergoing therapeutic hypothermia.

STUDY DESIGN

Retrospective observational single-center study.

SUBJECTS

27 consecutive asphyxiated full- or near-term newborns (25 under hypothermia) that underwent median nerve aEEG-SEPs as part of their clinical evaluation at the neonatal intensive care unit of Helsinki University Hospital.

OUTCOME MEASURES

aEEG-SEP classification (present, absent or unreliable) was compared to classification of SEPs recorded with a full EEG montage (EEG-SEP), and outcome determined from medical records at approximately 12-months-age. Unfavorable outcome included death, cerebral palsy, or severe epilepsy.

RESULTS

The aEEG-SEP and EEG-SEP classifications were concordant in 21 of the 22 newborns with both recordings available. All five newborns with bilaterally absent aEEG-SEPs had absent EEG-SEPs and the four with outcome information available had an unfavorable outcome (one was lost to follow-up). Of the newborns with aEEG-SEPs present, all with follow-up exams available had bilaterally present EEG-SEPs and a favorable outcome (one was lost to follow-up). One newborn with unilaterally absent aEEG-SEP at 25 h of age had bilaterally present EEG-SEPs on the next day, and a favorable outcome.

CONCLUSIONS

aEEG-SEPs recorded during therapeutic hypothermia on the first postnatal days are reliable for assessing brain injury severity. Adding SEP into routine aEEG brain monitoring offers an additional tool for very early outcome prediction after birth asphyxia.

Iron overload after allogeneic stem cell transplantation in children with acute lymphoblastic leukemia

Red blood cell transfusions are an essential part of supporting care in leukemia treatment. We examined the prevalence of iron overload and its effects on organ function and childhood growth in pediatric patients after allogeneic HSCT for acute lymphoblastic leukemia. Twenty-three patients were included (median age 12.6, range 7.5-21.4 years). Body iron load was determined using laboratory tests, hepatic and cardiac MRI, and by calculating iron received from transfusions. We performed multivariate analysis to determine association of body iron load with liver enzymes, cardiac function, insulin resistance, and growth. Median plasma ferritin was 344 (range 40-3235) ng/mL and exceeded 1000 ng/mL in three patients (13%). In MRI, 11 patients (48%) had hepatic iron overload and 1 patient (4%) myocardial iron overload. In cardiac MRI, 8 patients (35%) had significant but subclinical decrease in ejection fraction (median z-score -1.7, range -3.1-0.14), but cardiac function did not associate with iron status. Alanine transaminase associated with transfused iron per time unit (P = .001) after the median follow-up of 4.5 years. No correlation was found between iron load and growth or insulin resistance. Iron overload is common in children transplanted for ALL, but iron overload associated organ dysfunction is not present at early age. We recommend evaluation of iron load for all patients at least once during follow-up after transplantation.

Novel Hemizygous IL2RG p.(Pro58Ser) Mutation Impairs IL-2 Receptor Complex Expression on Lymphocytes Causing X-Linked Combined Immunodeficiency

Hypomorphic IL2RG mutations may lead to milder phenotypes than X-SCID, named variably as atypical X-SCID or X-CID. We report an 11-year-old boy with a novel c. 172C>T;p.(Pro58Ser) mutation in IL2RG, presenting with atypical X-SCID phenotype. We also review the growing number of hypomorphic IL2RG mutations causing atypical X-SCID. We studied the patient's clinical phenotype, B, T, NK, and dendritic cell phenotypes, IL2RG and CD25 cell surface expression, and IL-2 target gene expression, STAT tyrosine phosphorylation, PBMC proliferation, and blast formation in response to IL-2 stimulation, as well as protein-protein interactions of the mutated IL2RG by BioID proximity labeling. The patient suffered from recurrent upper and lower respiratory tract infections, bronchiectasis, and reactive arthritis. His total lymphocyte counts have remained normal despite skewed T and B cells subpopulations, with very low numbers of plasmacytoid dendritic cells. Surface expression of IL2RG was reduced on his lymphocytes. This led to impaired STAT tyrosine phosphorylation in response to IL-2 and IL-21, reduced expression of IL-2 target genes in patient CD4+ T cells, and reduced cell proliferation in response to IL-2 stimulation. BioID proximity labeling showed aberrant interactions between mutated IL2RG and ER/Golgi proteins causing mislocalization of the mutated IL2RG to the ER/Golgi interface. In conclusion, IL2RG p.(Pro58Ser) causes X-CID. Failure of IL2RG plasma membrane targeting may lead to atypical X-SCID. We further identified another carrier of this mutation from newborn SCID screening, lost to closer scrutiny.

Severe Phenotype of APECED (APS1) Increases Risk for Structural Bone Alterations

Objective: Immunological abnormalities, the resulting endocrinopathies and their treatments may impact bone health in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS1). The aim of the present study was to describe skeletal characteristics in patients with APECED and the prevalence and risk factors of compromised bone health. Patients and methods: We performed a cross-sectional study on 44 patients (27 females) with APECED and 82 age-, gender- and ethnicity-matched control subjects (54 females). We determined the prevalence of osteoporosis by dual-energy X-ray absorptiometry and skeletal characteristics by peripheral quantitative computed tomography at radius and tibia. Results: Patients were examined at the median age of 37.8 years (range, 7.0-70.1). Dual-energy X-ray absorptiometry indicated osteoporosis in four adult patients (9%); radiographs showed vertebral fractures in three patients. The prevalence of multiple non-spinal fractures was higher in patients than in controls. On peripheral quantitative computed tomography, bone characteristics at distal and proximal radius did not differ between the groups. At distal tibia, patients had lower total (p = 0.009) and trabecular (p = 0.033) volumetric bone mineral density. At the proximal tibia, patients had lower cortical thickness (p < 0.001) than controls. Severity of APECED phenotype influenced both radial and tibial characteristics: cortical thickness and total and trabecular volumetric bone mineral density were lower in patients with ≥7 disease manifestations as compared with more mildly affected patients, whose values were similar to controls. Conclusions: APECED associated with bone structural alterations, especially in patients with a high number of disease manifestations. This may increase the risk of fractures with aging, but symptomatic osteoporosis was rare.

PLS3 Mutations Cause Severe Age and Sex-Related Spinal Pathology

Objective: Mutations in the X-chromosomal PLS3-gene, encoding Plastin 3, lead to severe early-onset osteoporosis, suggesting a major role for PLS3 in bone metabolism. However, the consequences of abnormal PLS3 function in bone and other tissues remain incompletely characterized. This study evaluated spinal consequences of aberrant PLS3 function in patients with PLS3 mutations. Design: A cross-sectional cohort study with spinal magnetic resonance imaging of 15 PLS3 mutation-positive (age range 9-77 years) and 13 mutation-negative (9-70 years) subjects. Images were reviewed for spinal alignment, vertebral heights and morphology, intervertebral disc changes and possible endplate deterioration. Results: Vertebral changes were significantly more prevalent in the mutation-positive subjects compared with the mutation-negative subjects; they were most abundant in upper thoracic spine, and in all age groups and both sexes, although more prominent in males. Difference in anterior vertebral height reduction was most significant in T5 and T6 (p = 0.046 and p = 0.041, respectively). Mid-vertebral height reduction was most significant in T3 and T5 (p = 0.037 and p = 0.005, respectively), and, for male mutation-positive subjects only, in T4 and T6-10 (p = 0.005-0.030 for each vertebra). Most of the abnormal vertebrae were biconcave in shape but thoracic kyphosis or lumbar lordosis were unchanged. Vertebral endplates were well-preserved in the mutation-positive subjects with even fewer Schmorl nodes than the mutation-negative subjects (10 vs. 16). Conclusions: Compromised PLS3 function introduces severe and progressive changes to spinal structures that are present already in childhood, in both sexes and most abundant in upper thoracic spine. Cartilaginous structures are well-preserved.

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Letrozole versus testosterone for promotion of endogenous puberty in boys with constitutional delay of growth and puberty: a randomised controlled phase 3 trial

BACKGROUND

The treatment of constitutional delay of growth and puberty (CDGP) is an underinvestigated area in adolescent medicine. We tested the hypothesis that peroral aromatase inhibition with letrozole is more efficacious than intramuscular injection of low-dose testosterone in inducing puberty in boys with CDGP.

METHODS

We did a randomised, controlled, open-label trial at four paediatric centres in Finland. Boys aged at least 14 years with CDGP who wanted medical intervention and exhibited the first signs of puberty were randomly assigned in blocks of ten to receive either six intramuscular injections of low-dose testosterone (about 1 mg/kg bodyweight) every 4 weeks for 6 months or peroral letrozole 2·5 mg once daily for 6 months. All boys were followed up for 6 months after the end of treatment. The primary outcomes were changes in testicular volume and hormonal markers of puberty at 6 months after treatment initiation, which were assessed in all participants who received the assigned treatment. All patients were included in the safety analysis. This study is registered with ClinicalTrials.gov, number NCT01797718.

FINDINGS

Between Aug 1, 2013, and Jan 30, 2017, 30 boys were randomly assigned to receive testosterone (n=15) or letrozole (n=15). One boy in the testosterone group was excluded from the primary analyses because of a protocol deviation. During treatment, boys in the letrozole group had higher serum concentrations of luteinising hormone, follicle-stimulating hormone, testosterone, and inhibin B than did boys in the testosterone group. Testicular growth from baseline to 6 months was greater in the letrozole group than in the testosterone group (7·2 mL [95% CI 5·2-9·3] vs 2·2 mL [1·4-2·9]; between-group difference per month 0·9 mL [95% CI 0·6-1·2], p<0·0001). Most adverse events were mild. One boy in the testosterone group had aggressive behaviour for 1 week after each injection, and one boy in the letrozole group had increased irritability at 6 months.

INTERPRETATION

Letrozole might be a feasible alternative treatment to low-dose testosterone for boys with CDGP who opt for medical intervention. However, the risks and benefits of manipulating the reproductive axis during early puberty should be weighed carefully.

FUNDING

Helsinki University Hospital, Academy of Finland, and Finnish Foundation for Pediatric Research.

Letrozole Monotherapy in Pre- and Early-Pubertal Boys Does Not Increase Adult Height

Background: Aromatase inhibitors (AIs) have been used in boys with idiopathic short stature (ISS) to promote growth despite the lack of actual data regarding treatment effect on adult height. In this study, we characterized adult heights and long-term follow-up in AI-treated boys with ISS. Methods: Adult heights and long-term follow-up data, including spine MRIs, of a randomized, double-blind, placebo-controlled trial of boys who were treated with letrozole (Lz) (2.5 mg/d) or placebo (Pl) for 2 years during prepuberty and early puberty. The mean bone ages at treatment cessation were 10.2 and 10.8 years, respectively. Results: Adult heights were similar between the boys treated with Lz (n = 10) and those who received Pl (n = 10) (164.8 ± 4.0 vs. 163.7 ± 3.7 cm, p = 0.49, respectively). In either group, the adult heights did not differ from predicted adult heights at start of the study [Pl: 163.7 (3.7) cm vs. 166.9 (3.3), p = 0.06; Lz: 164.8 (4.0) cm vs. 167.6 (7.9), p = 0.20, respectively]. Long-term follow-up data showed that the frequency of subjects with a vertebral deformity was similar between the groups (Lz, 29% and Pl, 22%, p = 0.20), and no single comorbidity was clearly enriched in either group. Conclusions: The Lz-treated boys had similar adult heights with the subjects who received Pl for 2 years, which indicates that the treatment is not beneficial when given to pre- or early-pubertal boys. Previously observed vertebral deformities ameliorated during follow-up, which supports the skeletal safety of Lz therapy in children and adolescents.

Recessive multiple epiphyseal dysplasia - Clinical characteristics caused by rare compound heterozygous SLC26A2 genotypes

Pathogenic sequence variants in the solute carrier family 26 member 2 (SLC26A2) gene result in lethal (achondrogenesis Ib and atelosteogenesis II) and non-lethal (diastrophic dysplasia and recessive multiple epiphyseal dysplasia, rMED) chondrodysplasias. We report on two new patients with rMED and very rare compound heterozygous mutation combinations in non-consanguineous families. Patient I presented in childhood with waddling gait and joint stiffness. Radiographs showed epiphyseal changes, bilateral coxa plana-deformity and knee valgus deformity, for which he underwent surgeries. At present 33 years his height is 165 cm. Patient II presented with cleft palate, small jaw, short limbs, underdeveloped thumbs and on radiographs, cervical kyphosis with an underdeveloped C4. He also developed severe scoliosis but has grown at -2.9 SD curve. Molecular analysis revealed that patient I is heterozygous for two known pathogenic variants in SLC26A2, a splice site variant c.-26+2T > C and a missense variant c.1957T > A (p.Cys653Ser), while patient II is compound heterozygous for missense variants c.835C > T (p.Arg279Trp) and c.1535C > A (p.Thr512Lys). These patients further elucidate the variability of the phenotypic and genetic presentations of rMED.

Evoked potentials recorded during routine EEG predict outcome after perinatal asphyxia

OBJECTIVE

To evaluate the added value of somatosensory (SEPs) and visual evoked potentials (VEPs) recorded simultaneously with routine EEG in early outcome prediction of newborns with hypoxic-ischemic encephalopathy under modern intensive care.

METHODS

We simultaneously recorded multichannel EEG, median nerve SEPs, and flash VEPs during the first few postnatal days in 50 term newborns with hypoxic-ischemic encephalopathy. EEG background was scored into five grades and the worst two grades were considered to indicate poor cerebral recovery. Evoked potentials were classified as absent or present. Clinical outcome was determined from the medical records at a median age of 21months. Unfavorable outcome included cerebral palsy, severe mental retardation, severe epilepsy, or death.

RESULTS

The accuracy of outcome prediction was 98% with SEPs compared to 90% with EEG. EEG alone always predicted unfavorable outcome when it was inactive (n=9), and favorable outcome when it was normal or only mildly abnormal (n=17). However, newborns with moderate or severe EEG background abnormality could have either favorable or unfavorable outcome, which was correctly predicted by SEP in all but one newborn (accuracy in this subgroup 96%). Absent VEPs were always associated with an inactive EEG, and an unfavorable outcome. However, presence of VEPs did not guarantee a favorable outcome.

CONCLUSIONS

SEPs accurately predict clinical outcomes in newborns with hypoxic-ischemic encephalopathy and improve the EEG-based prediction particularly in those newborns with severely or moderately abnormal EEG findings.

SIGNIFICANCE

SEPs should be added to routine EEG recordings for early bedside assessment of newborns with hypoxic-ischemic encephalopathy.

Bisphosphonate Treatment and the Characteristics of Femoral Fractures in Children With Osteogenesis Imperfecta

CONTEXT

The short-term benefits of bisphosphonates (BPs) are evident in the treatment of children with osteogenesis imperfecta (OI), but some concerns related to long-term effects remain.

OBJECTIVE

To elucidate the effect of BPs on characteristics of femoral fractures in children with OI.

DESIGN AND SETTING

Retrospective cohort study at a university hospital.

PATIENTS AND MAIN OUTCOME MEASURE

The study included 93 patients with OI. We recorded fracture histories and analyzed all femoral fractures for location and fracture type using radiographs obtained at fracture diagnosis. Effects of BPs were evaluated by comparing fracture characteristics in three groups: patients (1) naive to BPs, (2) receiving ongoing BP treatment, and (3) whose treatment was discontinued.

RESULTS

In total, 127 femoral fractures occurred in 24 patients. Of the fractures, 63 (50%) occurred in patients naive to BPs, 44 (35%) during BP treatment, and 20 (16%) after treatment discontinuation. Mid or distal shaft fractures were most common (41%), followed by subtrochanteric (33%) and distal (20%) fractures. Almost all fractures were transverse (65%) or oblique (28%). The pattern of femoral fractures was similar in all three BP treatment groups (P = 0.78 for location; P = 0.35 for fracture type) and was not related to cumulative BP dose. Instead, OI type correlated with fracture characteristics, and distal location and transverse configuration were more common in the more severe types III and IV compared with type I OI.

CONCLUSION

Characteristics of femoral fractures in children with OI are affected by OI type but not by BP exposure.

Impaired growth and intracranial calcifications in autosomal dominant hypocalcemia caused by a GNA11 mutation

OBJECTIVE

Autosomal dominant hypocalcemia (ADH) is characterized by hypocalcemia and inappropriately low PTH concentrations. ADH type 1 is caused by activating mutations in the calcium-sensing receptor (CASR), a G-protein-coupled receptor signaling through α11 (Gα11) and αq (Gαq) subunits. Heterozygous activating mutations in GNA11, the gene encoding Gα11, underlie ADH type 2. This study describes disease characteristics in a family with ADH caused by a gain-of-function mutation in GNA11.

DESIGN

A three-generation family with seven members (3 adults, 4 children) presenting with ADH.

METHODS

Biochemical parameters of calcium metabolism, clinical, genetic and brain imaging findings were analyzed.

RESULTS

Sanger sequencing revealed a heterozygous GNA11 missense mutation (c.1018G>A, p.V340M) in all seven hypocalcemic subjects, but not in the healthy family members (n=4). The adult patients showed clinical symptoms of hypocalcemia, while the children were asymptomatic. Plasma ionized calcium ranged from 0.95 to 1.14mmol/L, yet plasma PTH was inappropriately low for the degree of hypocalcemia. Serum 25OHD was normal. Despite hypocalcemia 1,25(OH)2D and urinary calcium excretion were inappropriately in the reference range. None of the patients had nephrocalcinosis. Two adults and one child (of the two MRI scanned children) had distinct intracranial calcifications. All affected subjects had short stature (height s.d. scores ranging from -3.4 to -2.3 vs -0.5 in the unaffected children).

CONCLUSIONS

The identified GNA11 mutation results in biochemical abnormalities typical for ADH. Additional features, including short stature and early intracranial calcifications, cosegregated with the mutation. These findings may indicate a wider role for Gα11 signaling besides calcium regulation.

Metronomic therapy can increase quality of life during paediatric palliative cancer care, but careful patient selection is essential

AIM

Children with refractory or high-risk malignancies frequently suffer from poor quality of life during palliative care. This study explored the effect of metronomic drug administration on survival and quality of life in paediatric patients with various refractory or high-risk tumours.

METHODS

We treated 17 patients with a maintenance therapy that consisted of metronomic thalidomide, etoposide and celecoxib. The endpoints of the study were overall and progression-free survival, changes in the Karnofsky-Lansky scores from baseline to the end of the study therapy and radiological responses.

RESULTS

The median overall survival after the start of the study therapy was 6.2 months (range 2.0-57.7), and the six-, 12- and 24-month survival rates were 59%, 18% and 18%, respectively. The median progression-free survival was 3.2 months (range 0.3-17.8). The Karnofsky-Lansky scores increased significantly during the study therapy (p = 0.02), with 35% of the patients having a transient improvement in their clinical status. Radiologically, one partial response and two disease stabilisations were encountered. Grade III-V adverse events occurred in 76% of the patients.

CONCLUSION

Metronomic therapy may increase the quality of life during palliative care for childhood cancer, but requires careful patient selection to minimise the risk of serious adverse events.

Bone marrow fat unsaturation in young adults is not affected by present or childhood obesity, but increases with age: A pilot study

OBJECTIVES

Obesity increases bone marrow fat (BMF) content. The association between early obesity and bone marrow fatty acid composition is unknown. We measured BMF unsaturation index (UI) in normal-weight and overweight young adults with a known weight status in early childhood and tested the relationship between BMF UI and exercise history, glycemic state, and other clinical characteristics.

METHODS

The study included 18 normal-weight (BMI <25 kg/m(2); 2 males, 16 females) and 17 overweight (BMI ≥25 kg/m(2); 9 males, 8 females) young adults aged 15-27 years. BMF UI was assessed with magnetic resonance proton spectroscopy optimized to reduce water interference. Exercise information was obtained with a pedometer accompanied with the history of recent physical activity. Blood samples (insulin, glucose, HbA1c) and body characteristics (BMI, waist-to-hip ratio, body fat composition) were assessed.

RESULTS

BMF UI was not affected by obesity at the time of study or before age 7 years. BMF UI increased with age in normal-weight and overweight subjects (R=0.408, p=0.015) but did not associate with gender, physical activity or body fat composition; a suggestive association was observed with glucose (R=-0.289, p=0.10).

CONCLUSIONS

The association of BMF UI with age in early adulthood may represent normal maturation of bone marrow. There was a trend toward an association with blood glucose, warranting further studies.

A novel splice mutation in PLS3 causes X-linked early onset low-turnover osteoporosis

Genetic factors play an important role in the development of osteoporosis. Several monogenic forms of osteoporosis have been recognized, most recently an X-chromosomal form resulting from mutations in the gene encoding plastin 3 (PLS3). PLS3 is a protein involved in actin bundle formation in the cytoskeleton. We present a large family with early onset osteoporosis and X-linked inheritance. Phenotyping was performed on 19 family members and whole-exome sequencing on 7 family members (5 with a diagnosis of early onset osteoporosis and 2 with normal bone parameters). Osteoporosis had its onset in childhood and was characterized by recurrent peripheral fractures, low bone mineral density (BMD), vertebral compression fractures, and significant height loss in adulthood. Males were in general more severely affected than females. Bone histomorphometry findings in 4 males and 1 female showed severe trabecular osteoporosis, low amount of osteoid, and decreased mineral apposition rate, indicating impaired bone formation; resorption parameters were increased in some. All affected subjects shared a single base substitution (c.73-24T > A) in intron 2 of PLS3 on Xq23. The mutation, confirmed by Sanger sequencing, segregated according to the skeletal phenotype. The mutation introduces a new acceptor splice site with a predicted splice score of 0.99 and, thereby, as confirmed by cDNA sequencing, induces the insertion of 22 bases between exons 2 and 3, causing a frameshift and premature termination of mRNA translation (p.Asp25Alafs*17). The mutation affects the first N-terminal calcium-binding EF-hand domain and abolishes all calcium- and actin-binding domains of the protein. Our results confirm the role of PLS3 mutations in early onset osteoporosis. The mechanism whereby PLS3 affects bone health is unclear, but it may be linked to osteocyte dendrite function and skeletal mechanosensing. Future studies are needed to elucidate the role of PLS3 in osteoporosis and to define optimal treatment.

Compromised peak bone mass in patients with inflammatory bowel disease--a prospective study

OBJECTIVE

To evaluate peak bone mass attainment in children and adolescents with inflammatory bowel disease and to identify risk factors for suboptimal bone mass attainment.

STUDY DESIGN

We conducted a prospective follow-up study of 47 children and adolescents (24 males) with ulcerative colitis (n = 30) or Crohn's disease (n = 17). They were assessed for lumbar spine areal bone mineral density (aBMD) and for height-adjusted whole body less head bone mineral content (BMC); the values were corrected for bone age.

RESULTS

Altogether, 73% of the patients had completed pubertal development after the median follow-up time of over 5 years. Despite clinical inactivity of the disease in 70% of the patients at the follow-up visit, BMD or BMC Z-scores improved in none of the measurement sites. Lumbar spine aBMD Z-scores (mean difference [95% CI], -0.47 [-0.92 to -0.03]; P = .04) and whole body less head BMC height- and bone age-adjusted Z-scores (-0.52 [-1.01 to -0.02]; P = .04) decreased in patients who were pubertal at baseline and completed their pubertal development during the follow-up. Postpubertal patients had lower aBMD and BMC Z-scores in comparison with prepubertal and pubertal patients. Low lumbar spine aBMD (Z-score < -1.0) was associated with completed pubertal development, underweight, and greater lifetime cumulative weight-adjusted prednisolone dose. Vertebral fractures were detected in 3 patients (6%). One-fourth of the patients had insufficient serum 25-hydroxyvitamin D concentrations (<50 nmol/L).

CONCLUSIONS

The longitudinal follow-up over the pubertal years shows that inflammatory bowel disease poses a significant threat for bone health. The suboptimal peak bone mass attainment may have life-long consequences.

Hypoplastic anemia in cartilage-hair hypoplasia-balancing between iron overload and chelation

OBJECTIVE

To evaluate the severity of iron overload and the success of iron chelation therapy in patients with cartilage-hair hypoplasia (CHH) and hypoplastic anemia, with particular focus on adverse effects of iron chelators.

STUDY DESIGN

Four of the 23 presently surviving Finnish patients with CHH under 18 years of age are dependent on regular red blood cell transfusions. Their hospital records were reviewed for history of anemia and chelation therapy. Cumulative iron load from transfusions was calculated. Efficacy of the chelation therapy was evaluated biochemically and by liver iron content assessments.

RESULTS

At the introduction of iron chelation, the patients had received on average 99 (37-151) transfusions; the mean cumulative iron overload was 4640 (800-8200) mg, the annual iron accumulation rate 0.35 (0.25-0.41) mg/kg/d, and the mean plasma ferritin was 2896 (1217-6240) μg/L. Liver iron content, determined by biopsy in 3 patients, was on average 20.0 (6.6-30.0) mg/g liver dry weight. All patients, except 1 with Hirschsprung disease, tolerated deferoxamine, deferiprone, and deferasirox therapy well, showing only mild adverse effects typical for the agents. Plasma ferritin levels and liver magnetic resonance imaging T2* of iron overload showed successful chelation.

CONCLUSION

Iron chelation is well tolerated in patients with CHH, with possible exception of patients with Hirschsprung disease. Successful chelation will prepare for hematopoietic stem cell transplantation in patients with CHH with persistent transfusion dependency.

Long-term skeletal consequences of childhood acute lymphoblastic leukemia in adult males: a cohort study

OBJECTIVE

Long-term health sequelae of childhood-onset acute lymphoblastic leukemia (ALL) remain largely unknown. Low bone mineral content (BMC) and bone mineral density (BMD) are recognized complications, but it is unknown whether these persist until adulthood. We evaluated skeletal characteristics and their association with ALL therapy in long-term male ALL survivors.

DESIGN

This cross-sectional cohort study included 49 long-term male ALL survivors and 55 age-matched healthy males.

METHODS

BMD and compression fractures were assessed by dual-energy X-ray absorptiometry; blood biochemistry was obtained for parameters of calcium homeostasis.

RESULTS

The ALL survivors (median age 29 years, range 25-38 years), assessed 10-38 years after ALL diagnosis, had lower lumbar spine (P<0.001), femoral neck (P<0.001), and whole-body (P=0.017) BMD than expected based on normative values. When compared with the controls (median age 30 years, range 24-36 years), the ALL survivors had lower lumbar spine BMC (P=0.014), lower whole-body BMC (P<0.001), and lower whole-body BMD (P<0.001), but the differences were partly explained by differences in height. Altogether, 20% of the ALL survivors had spinal compression fractures, but these were equally prevalent in the controls. Males diagnosed with ALL before age 5 years had significantly lower BMD values. Other recognized risk factors included untreated hypogonadism, vitamin D deficiency, hypophosphatemia, low IGF-binding protein-3, and low physical activity.

CONCLUSIONS

At young adulthood, long-term male ALL survivors have significantly reduced BMC and BMD and a high prevalence of spinal compression fractures. Careful follow-up and active treatment of the recognized risk factors are warranted.

Anti-tumor necrosis factor treatment in cherubism--clinical, radiological and histological findings in two children

Cherubism is a rare and disfiguring genetic disorder with excessive bone resorption and multilocular lesions in the mandible and/or maxilla. The disease-causing gain-of-function mutations in the SH3-binding protein 2 (SH3BP2) gene result in increased myeloid cell responses to macrophage colony stimulating factor and RANK ligand, formation of hyperactive osteoclasts (giant cells), and hyper-reactive macrophages that produce excessive amounts of the inflammatory cytokine tumor necrosis factor α (TNF-α). Recent findings in the cherubism mouse model suggest that TNF-α plays a major role in disease pathogenesis and that removal of TNF-α prevents development of the bone phenotype. We treated two children with cherubism with the TNF-α antagonist adalimumab for approximately 2.5 years and collected extensive clinical, radiological and histological follow-up data during the treatment. Histologically the treatment resulted in a significant reduction in the number of multinucleated giant cells and TNF-α staining positivity in both patients. As evaluated by computed tomography and magnetic resonance imaging, the lesions in Patient 1 showed either moderate enlargement (mandibular symphysis) or remained stable (mandibular rami and body, the maxilla). In Patient 2, the lesions in mandibular symphysis showed enlargement during the first 8 months of treatment, and thereafter the lesions remained unchanged. Bone formation and resorption markers remained unaffected. The treatment was well tolerated. Based on our findings, TNF-α antagonist may decrease the formation of pathogenic giant cells, but does not result in lesion regression or prevent lesion expansion in active cherubism. TNF-α modulator treatment thus does not appear to provide sufficient amelioration for patients suffering from cherubism.

Neuroimaging and neurological findings in patients with hypochondroplasia and FGFR3 N540K mutation

Hypochondroplasia (HCH), an autosomal dominant skeletal dysplasia caused by mutations in the FGFR3 gene, has not been commonly associated with neurological problems. Temporal lobe dysgenesis associated with epilepsy was recently described in single patients. In this retrospective study, we assessed neurological and neuroimaging aspects of 13 FGFR3 (N540K) mutation verified HCH patients in Finland. Eight patients had neurocognitive difficulties, ranging from specific learning disorder (2/13) to mild intellectual disability (5/13) or global developmental delay (1/13). Six of 13 patients had a history of seizures or epilepsy. Eight patients had undergone MRI. They all had structural abnormalities consistent with temporal lobe dysgenesis. Six patients had peritrigonal white matter reduction, and 4 had abnormally shaped lateral ventricles. We recommend a close follow-up of development in patients with HCH and a low threshold for neuroimaging.

Frontotemporal pachygyria-two new patients

We describe two Finnish brothers with frontotemporal pachygyria, intellectual deficiency and mild dysmorphisms. Previously, only a few cases of similar frontotemporal pachygyria have been reported. This report provides further evidence about frontotemporal pachygyria being a distinct genetic entity inherited as an autosomal recessive trait.

Impaired bone health in inflammatory bowel disease: a case-control study in 80 pediatric patients

Previous studies have indicated that children with inflammatory bowel disease (IBD) may not achieve optimal bone mass. We evaluated the skeletal characteristics in children and adolescents with IBD. This cross-sectional cohort study comprised 80 IBD patients (median age 14.9 years, range 5-20) with a median disease duration of 3.4 years; 51 had ulcerative colitis, 26 Crohn disease, and 3 unspecified colitis. Eighty age- and gender-matched healthy subjects served as controls. Areal bone mineral density (aBMD), body composition, and vertebral fractures (VFs) were assessed by DXA. Bone age (BA) was determined for IBD patients. Findings were correlated with disease- and treatment-related parameters and biochemistry. IBD patients had lower BA-adjusted lumbar spine and whole-body aBMD (p < 0.001 for both) and whole-body BMC adjusted for height (p = 0.02) than controls. Lean mass and fat mass Z scores did not differ between the groups, but IBD patients had lower whole-body BMC relative to muscle mass (p = 0.006). Despite vitamin D supplementation in 48 %, vitamin D deficiency was common. In IBD cumulative weight-adjusted prednisolone dose >150 mg/kg for the preceding 3 years increased the risk for low whole-body aBMD (OR = 5.5, 95 % CI 1.3-23.3, p = 0.02). VFs were found in 11 % of patients and in 3 % of controls (p = 0.02). IBD in childhood was associated with low aBMD and reduced bone mass accrual relative to muscle mass; the risk for subclinical VFs may be increased. These observations warrant careful follow-up and active preventive measures.

Impaired bone health and asymptomatic vertebral compressions in fracture-prone children: a case-control study

Frequent fractures in children may be a sign of impaired bone health, but it remains unestablished when and how fracture-prone children should be assessed. This prospective study elucidated skeletal characteristics and predisposing factors in children with recurrent fractures. Findings were used to establish guidelines for screening. During a 12-month period we recorded fracture history for all children (n = 1412) treated for an acute fracture at a large university hospital. All apparently healthy children over 4 years of age, who had sustained: (1) at least one vertebral fracture; (2) two long-bone fractures before age 10 years; or (3) three long-bone fractures before age 16 years, were recruited. They underwent dual-energy X-ray absorptiometry (DXA), laboratory tests, and spinal radiography. Information regarding family history and lifestyle factors were collected. Findings were compared with healthy controls. Sixty-six fracture-prone children (44 males, mean age 10.7 years; 5% of all children with fractures) were identified. Altogether, they had sustained 183 long-bone fractures (median 3, range 0–7); 11 children had sustained vertebral fracture(s). Patients had significantly lower bone mineral density (BMD) at lumbar spine (p < 0.001), hip (p = 0.007), and whole body (p < 0.001) than the controls; only 5 children (8%) had a BMD Z-score < −2.0. Asymptomatic vertebral compressions were prevalent, especially in those under 10 years of age. Hypercalciuria (11%) and hyperphosphaturia (22%) were significantly more prevalent than in controls. Serum concentration of 25-hydroxyvitamin D (S-25OHD) was below 50 nmol/L in 55%; low levels were associated with low BMD and vertebral compressions. The fracture-prone children had lower calcium intake, less physical activity, and more often had siblings with fractures than the controls. The findings suggest that a thorough pediatric evaluation, including DXA and spinal radiography, is often indicated already after a second significant low-energy fracture in children, in order to detect potentially preventable adverse lifestyle factors and nutritional deficits and to identify those with compromised overall bone health.

Draft consensus guidelines for diagnosis and treatment of Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic exocrine insufficiency and bone marrow failure, often associated with neurodevelopmental and skeletal abnormalities. Mutations in the SBDS gene have been shown to cause SDS. The purpose of this document is to provide draft guidelines for diagnosis, evaluation of organ and system abnormalities, and treatment of hematologic, pancreatic, dietary, dental, skeletal, and neurodevelopmental complications. New recommendations regarding diagnosis and management are presented, reflecting advances in understanding the genetic basis and clinical manifestations of the disease based on the consensus of experienced clinicians from Canada, Europe, and the United States. Whenever possible, evidence-based conclusions are made, but as with other rare diseases, the data on SDS are often anecdotal. The authors welcome comments from readers.

The thoracic and lumbar spine in severe juvenile idiopathic arthritis: magnetic resonance imaging analysis in 50 children

OBJECTIVE

To determine the prevalence of vertebral fractures as a complication of juvenile idiopathic arthritis (JIA).

STUDY DESIGN

This cross-sectional study evaluated the prevalence and characteristics of spinal abnormalities in 50 children (aged 7.0-18.7 years) with treatment-resistant JIA by magnetic resonance imaging. Vertebral deformities, endplate irregularities, intervertebral disc involvement, spinal canal, neural foramina, and back muscles were analyzed and correlated with clinical characteristics and bone mineral density.

RESULTS

Magnetic resonance imaging revealed various abnormalities in 31 patients (62%). Vertebral compression was seen in 28%, disc degeneration in 46%, protrusions in 14%, prolapses in 4%, endplate changes in 26%, and anterior vertebral corner lesions in 16%. Two patients (4%) had mild spinal canal narrowing without medullar involvement; none had neural root compression. Six patients (12%) had mild back muscle atrophy. No correlation was observed between spinal fractures or other vertebral changes and disease activity or duration, pain or bone mineral density; patients with spinal fractures tended to have a higher recent glucocorticoid exposure (P=.086).

CONCLUSION

Children with severe JIA have a high prevalence of compression fractures and other vertebral, endplate, and disc abnormalities in the thoracic and lumbar spine.

Zoledronic acid treatment in children with osteogenesis imperfecta

BACKGROUND

Intravenous disodium pamidronate has become an established treatment in osteogenesis imperfecta (OI). Another bisphosphonate, zoledronic acid, has been indicated for the treatment of adult osteoporosis. We studied its efficacy and safety in children with mild OI.

METHODS

Patients were treated for 1.0-3.2 years with 0.05 mg/kg zoledronic acid intravenously every 6 months as part of their clinical care. They were carefully followed for clinical and biochemical parameters, side effects, bone mineral densities (BMD) and compression fractures.

RESULTS

The study included 17 patients (age 1.5-16.8 years) with type I OI. They had sustained altogether 73 fractures; 9 had compression fractures. During the treatment, 6 patients suffered in total 10 new long-bone fractures. The median lumbar spine areal BMD z-score increased from -2.0 to -0.7 during 2 years of treatment. The infusions were associated with a transient decrease in serum calcium and phosphate and a significant increase in serum PTH. Two patients developed symptomatic hypocalcemia. Bone turnover markers decreased during the treatment.

CONCLUSIONS

Intravenous zoledronic acid is an effective mode of treatment in children with OI. The treatment response is comparable to pamidronate but the infusion protocol is more convenient. Further studies are needed to establish optimal dosing and long-term safety.

Cerebroretinal microangiopathy with calcifications and cysts: characterization of the skeletal phenotype

Cerebral cysts and calcifications with leukoencephalopathy and retinal vascular abnormalities are diagnostic hallmarks of cerebroretinal microangiopathy with calcifications and cysts (CRMCC). Previous studies have suggested that skeletal involvement is also common, but its characteristics remain unknown. This study aimed to assess the skeletal phenotype in CRMCC. All Finnish patients with features consistent with CRMCC and for whom radiographs were available were included. Clinical information pertinent to the skeletal phenotype was collected from hospital records, and all plain radiographs were reviewed for skeletal features. Bone mineral density (BMD) was measured by DXA. In one patient, bone biopsies were obtained for bone histology and histomorphometric analyses. The LRP5 gene was analyzed for mutations by direct sequencing. Our results show that the skeletal phenotype in CRMCC includes (1) compromised longitudinal growth pre- and postnatally, (2) generalized osteopenia or early onset low turnover osteoporosis with fragility fractures, and (3) metaphyseal abnormalities that may lead to limb deformities such as short femoral neck or genua valga. DXA measurements in three patients showed low BMD, and bone biopsies in the fourth patient with pathological fractures and impaired fracture healing showed low-turnover osteoporosis, with reduced osteoclast and osteoblast activity. Direct sequencing of all LRP5 coding exons and exon-intron boundaries in six patients with CRMCC revealed no putative mutations. We conclude that the CRMCC-associated bone disease is characterized by low BMD and pathological fractures with delayed healing, metaphyseal changes, and short stature pre- and postnatally. LRP5 is not a disease-causing gene in CRMCC.

Vertebral morphology in aromatase inhibitor-treated males with idiopathic short stature or constitutional delay of puberty

Aromatase inhibitors (AIs), blockers of estrogen biosynthesis, delay bone maturation and therefore are used increasingly to promote growth in children and adolescents with growth disorders. The effects of treatment on skeletal health are largely unknown. Since estrogen deficiency is associated with various detrimental skeletal effects, we evaluated in this cross-sectional posttreatment study vertebral body morphology, dimensions and endplates, and intervertebral disks by the use of magnetic resonance imaging (MRI) in two cohorts of males previously treated with the AI letrozole or placebo. Males with idiopathic short stature received treatment with letrozole or placebo for 2 years during prepuberty or early puberty; males with constitutional delay of puberty received letrozole or placebo in combination with low-dose testosterone for 1 year during early or midpuberty. In males with idiopathic short stature, mild vertebral body deformities were found in 5 of 11 (45%) letrozole-treated subjects, whereas in the placebo group no deformities were detected (p = .01). In the cohort of males with constitutional delay of puberty, a high prevalence of endplate and intervertebral disk abnormalities was observed in both the letrozole- and the placebo-treated groups. We conclude that AI therapy during prepuberty or early puberty may predispose to vertebral deformities, which probably reflect impaired vertebral body growth rather than impaired bone quality and compression fractures. If AIs are used in growth indications, follow-up of vertebral morphology is indicated.

Low density lipoprotein receptor-related protein 5 (LRP5) mutations and osteoporosis, impaired glucose metabolism and hypercholesterolaemia

OBJECTIVE

Mutations in the low-density lipoprotein receptor-related protein 5 gene (LRP5) underlie osteoporosis-pseudoglioma syndrome. Animal models implicate a role for LRP5 in lipid and glucose homeostasis. The objective was to evaluate metabolic consequences of LRP5 mutations in humans.

DESIGN AND PATIENTS

Thirteen Finnish individuals with homozygous or heterozygous LRP5 mutations were assessed for bone health, glucose and lipid metabolism, and for serum serotonin concentration. Results were compared with findings in family members without mutations.

MEASUREMENTS

Bone mineral density (BMD), vertebral morphology, oral and intravenous glucose tolerance tests, lipid profile and serum serotonin concentrations.

RESULTS

Two individuals were homozygous for R570W, one compound heterozygous for R570W and R1036Q, and 10 were heterozygous (six for R570W, three for R1036Q and one for R925C). Subjects with two LRP5 mutations had multiple spinal fractures and low BMD. Subjects with one mutation had significantly lower median lumbar spine (P = 0.004) and femoral neck (P = 0.005) BMD Z-scores, and more often vertebral fractures than the 18 individuals without mutations. Of the 12 subjects with LRP5 mutation six had diabetes and one had impaired glucose tolerance. Intravenous glucose tolerance tests suggested impaired beta-cell function; no insulin resistance was observed. Prevalence of hypercholesterolaemia was similar in mutation positive and negative subjects. Serum serotonin concentrations showed a trend towards higher concentrations in subjects with LRP5 mutation.

CONCLUSIONS

We found high prevalence of osteoporosis and abnormal glucose metabolism in subjects with LRP5 mutation(s). Further studies are needed to establish the role of LRP5 in glucose and lipid metabolism.

[Shwachman-Diamond syndrome--a diagnostic challenge]

Shwachman-Diamond syndrome is a rare autosomal recessive disorder caused by mutations in the SBDS gene. The cardinal symptoms arise from exocrine pancreatic insufficiency and bone marrow dysfunction. These lead to malabsorption and haematological abnormalities, susceptibility to infections and to increased risk of leukaemia. Skeletal involvement presents as growth failure, metaphyseal dysplasia and osteoporosis. The majority of patients also have liver dysfunction, learning difficulties and oral and dental problems. Although the disease typically presents in early childhood, phenotypic features change over time and the diagnosis becomes more challenging.

The natural history of Shwachman-Diamond syndrome-associated liver disease from childhood to adulthood

OBJECTIVES

In order to characterize the natural course of Shwachman-Diamond syndrome (SDS)-associated hepatopathy we evaluated liver biochemistry and imaging findings, and their evolution with age, in patients with SDS and verified SBDS mutations.

STUDY DESIGN

Retrospective and cross-sectional liver imaging, biochemical and histologic data of 12 patients (age range 2.1 to 37 years) with SBDS mutations were analyzed. Hepatic volume and parenchymal structure were determined from magnetic resonance imaging data.

RESULTS

Hepatomegaly and aminotransaminase elevation was observed in most of the patients with SDS at an early age; values normalized by age 5 years and remained normal over extended follow-up. Mild to moderate serum bile acid elevation was noted in 7 patients (58%). On magnetic resonance imaging, no patients (n = 11) had evidence of hepatic steatosis, cirrhosis, or fibrosis. Three middle-aged patients had hepatic microcysts.

CONCLUSIONS

SDS-associated hepatopathy has overall good prognosis. No major hepatic abnormalities developed during extended follow-up to adulthood. Mild cholestasis in follow-up even after normalization of transaminase levels may reflect primary alterations in liver metabolism in SDS.

Impact of aromatase inhibitor therapy on bone turnover, cortical bone growth and vertebral morphology in pre- and peripubertal boys with idiopathic short stature

In this randomized placebo-controlled study we examined the influence of aromatase inhibition on bone turnover, cortical bone growth, and vertebral body morphology in peripubertal boys. Thirty peripubertal boys with idiopathic short stature were treated with the aromatase inhibitor letrozole or placebo for 2 years. During treatment and posttreatment follow-up, dual-energy X-ray absorptiometry (DXA)-assessed bone mineral density, metacarpal index (MCI), and markers of bone turnover were examined. Vertebral morphology was examined by DXA after cessation of treatment. In letrozole-treated boys, the concentrations of the bone resorption marker urine aminoterminal telopeptide of type I collagen initially increased and thereafter slowly declined while the concentrations of the bone formation markers serum aminoterminal propeptide of type I collagen and serum alkaline phosphatase remained unchanged or slightly increased, respectively. In placebo-treated boys, all markers of bone turnover increased significantly during treatment. Among those who progressed into puberty, metacarpal index (MCI) increased more in the letrozole-treated than in the placebo-treated boys during treatment (25 vs. 9%, p = 0.007). The change in MCI correlated with the testosterone-to-estradiol ratio (r = 0.59, p = 0.02). Vertebral deformities were detected in 6 out of 13 boys receiving letrozole and in 4 out of 11 receiving placebo (p = 0.70). Aromatase inhibition suppresses bone turnover, possibly through an androgen-mediated effect. In pubertal boys, treatment stimulates cortical bone growth by increasing the testosterone-to-estradiol ratio.

Myocardial function in patients with Shwachman-Diamond syndrome: aspects to consider before stem cell transplantation

BACKGROUND

Early studies have suggested increased risk of fatal cardiac complications in infants with Shwachman-Diamond syndrome (SDS), an inherited bone marrow failure syndrome. Patients undergoing stem cell transplantation (STC) have appeared susceptible to organ toxicity, including cardiac involvement.

PROCEDURE

This study assessed anatomical and functional features of the heart in SDS. Eight patients (mean age 24.1 years, range 7-37 years, seven males) with SDS and confirmed SBDS mutations were prospectively assessed for cardiac anatomy, myocardial wall properties, and systolic and diastolic function. The study protocol included conventional echocardiography (n = 8) complemented by exercise Tissue-Doppler echocardiography (n = 7), and by MRI (n = 6).

RESULTS

No abnormalities in cardiac anatomy or function were observed in baseline clinical assessment, EKG, or conventional echocardiographic and MRI measurements. Myocardial structure and left ventricular (LV) mass were normal. The maximum isovolumic acceleration (IVA) value during exercise in Tissue-Doppler was significantly lower (P < 0.001), and the right ventricular (RV) ejection fraction (P = 0.02) and peak filling rate (PFR, P = 0.008) at rest in MRI were higher in patients.

CONCLUSIONS

Children and young adults with SDS and mutations in SBDS had normal cardiac anatomy and myocardial structure. Subtle RV diastolic function alterations at rest and depressed LV contractility during exercise were observed. Further studies are warranted to evaluate the clinical importance of these findings.

Patients with cartilage-hair hypoplasia have an increased risk for bronchiectasis

OBJECTIVE

To assess the prevalence, predictors, and course of bronchiectasis in patients with cartilage-hair hypoplasia.

STUDY DESIGN

Patients who had undergone high-resolution computed tomography of the lungs or bronchography were included in the study. Hospital records were coorelated for clinical features, respiratory symptoms, and laboratory variables. Imaging studies were correlated for changes suggestive of bronchiectasis and findings correlated with clinical and immunological measurements.

RESULTS

The study included 15 patients (5 male; median height Z-score, -7.7) aged from 2 to 39 years (median, 10 years). Cell-mediated immunity was impaired in 79% of the subjects, and humoral immunity was impaired in 71% of the subjects. 8 patients (52%) had bronchiectasis, diagnosed by means of high-resolution computed tomography (n = 6) or bronchography (n = 2). The findings ranged from localized mild dilatation of the airways to severe bronchiectasis with saccular airway dilatation. Bronchiectasis progressed during follow-up in 2 patients. Patients with bronchiectasis tended to have more severe growth failure and more often had defective humoral immunity than the general cartilage-hair hypoplasia population.

CONCLUSION

Patients with cartilage-hair hypoplasia are at risk of the development of bronchiectasis.

Magnetic resonance imaging findings of the pancreas in patients with Shwachman-Diamond syndrome and mutations in the SBDS gene

Pancreatic MRI was evaluated in 14 patients with a clinical diagnosis of Shwachman-Diamond syndrome, and the findings were correlated with Shwachman-Bodian-Diamond gene (SBDS) genotype. The findings suggest that patients with mutations in the SBDS gene have a characteristic magnetic resonance imaging pattern of fat-replaced pancreas and that SBDS mutations are unlikely in patients without this pattern.

Shwachman-Diamond syndrome is associated with low-turnover osteoporosis

INTRODUCTION

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow dysfunction. These result in malabsorption and hematological abnormalities. A skeletal dysplasia is also an integral feature of SDS. The present study assessed prevalence and determinants of osteopenia and osteoporosis in patients with SDS and disease-causing mutations in the SBDS gene.

MATERIALS AND METHODS

Eleven patients (8 males) aged from 5 to 37 years (median 16.7 years) with a genetically confirmed diagnosis of SDS were assessed for fracture history, bone mineral content (BMC), lean tissue mass (LTM) and bone mineral density (BMD) (Hologic Discovery A), osteoporotic vertebral changes, and for blood biochemistry and hematological parameters. Iliac crest bone biopsies were obtained from four patients for histology and histomorphometry.

RESULTS

The main findings were: (1) markedly reduced BMD Z-scores at the lumbar spine (median -2.1, range -4.4 to -0.8), proximal femur (median -1.3, range -2.2 to -0.7) and, whole body (median -1.0, range -2.8 to +0.6), and reduced Z-scores for height-adjusted BMC/LTM ratio (median -0.9, range -3.6 to +1.1); (2) vertebral compression fractures in three patients; and (3) blood biochemistry suggestive of mild vitamin D and vitamin K deficiency. Bone biopsies in four patients showed significant low-turnover osteoporosis with reduced trabecular bone volume, low numbers of osteoclasts and osteoblasts, and reduced amount of osteoid.

CONCLUSIONS

The results suggest that in addition to the skeletal dysplasia, SDS is associated with a more generalized bone disease characterized by low bone mass, low bone turnover and by vertebral fragility fractures. Osteoporosis may result from a primary defect in bone metabolism, and could be related to the bone marrow dysfunction and neutropenia.

Bone densitometry in the diagnosis of vertebral fractures in children: accuracy of vertebral fracture assessment

BACKGROUND

DXA scanner derived images of the spine are used for vertebral fracture detection in adults. It is unknown whether the method could be used in pediatrics. This study evaluated the diagnostic accuracy of DXA images in vertebral fracture assessment (VFA) in children.

METHODS

The study included 65 children (37 males; median age 12.1 years) with primary or secondary osteoporosis. Data on clinical history were collected from hospital records. Patients were assessed for spinal compression fractures by standard spinal radiographs and by bone densitometry (Hologic Discovery A) derived VFA images. The visibility and morphology of each vertebra in VFA images was assessed by two readers and by a semi-computerized software developed for the DXA scanner. The findings were compared with those in spinal radiographs and correlated with clinical parameters.

RESULTS

The visibility of vertebrae in VFA images was good in T8-L4 but compromised in the upper thoracic region (T4-T7) and was constantly inferior to that in standard radiographs. A total of 25 vertebral fractures were diagnosed in radiographs, but only 9 (36%) of these also in VFA images. The semi-computerized software could not accurately detect vertebrae in most of the children; accuracy increased with increasing age, height and BMD but was not sufficient to detect vertebral fractures.

CONCLUSIONS

The utility of DXA scanner derived images of the spine in vertebral fracture detection in children is limited by compromised visibility and poor diagnostic accuracy. The semi-computerized software is not suitable for pediatric use. These limitations should be kept in mind when assessing pediatric patients for osteoporosis.