Normal growth and intravascular volume status with good metabolic control during peritoneal dialysis in infancy.

The most demanding patient population on peritoneal dialysis (PD) consists of children under 2 years of age. Their growth is inferior to that of older children and maintaining euvolemia is difficult, especially in anuric patients. In this prospective study reported here, we enrolled 21 patients <2 years of age (mean 0.59 years) at onset of PD and monitored their uremia parameters and evaluated their nutrition. Since no good instrument currently exists for estimating intravascular volume status, we used traditional blood pressure measurements, echocardiography, and N-terminal atrial natriuretic peptide measurements. Growth was compared with midparental height. Metabolic control was good. Long-term hypertension was seen in 43% of the patients, but left ventricular hypertrophy decreased during the study period. Mean weekly urea Kt/V was 3.38 +/- 0.66 and creatinine clearance was 49 +/- 20 L/week per 1.73 m(2). Catch-up growth was documented in 57% of the patients during PD. However, these children did not attain their midparental height at the end of PD at a mean age of 1.71 years. Although favorable metabolic control and good growth were achieved during PD, these children lagged in term of their midparental height. We conclude that several instruments are needed for determining the management of intravascular volume status and that the control of calcium-phosphorus status is demanding.

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.

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.

Metabolic control and growth during exclusive growth hormone treatment in X-linked hypophosphatemic rickets.

BACKGROUND: GH may improve phosphate balance and height in X-linked hypophosphatemic rickets (XLH). This study evaluated the impact of exclusive rhGH therapy on phosphate homeostasis and growth. METHODS: Ten children (median age 12.2 years) with XLH were included in a 12-month trial with GH. Conventional treatment was discontinued 1 month prior GH (0.033 mg/kg/day); 1alpha-hydroxyvitamin D was added at 6 months and oral phosphate at 12 months, when GH was discontinued. Patients were followed 1-3 monthly until 18 months for clinical, biochemical and radiographic parameters. RESULTS: Serum phosphate Z-score increased significantly from baseline at 6 months (p = 0.005) and 9 months (p = 0.009) but returned to baseline by 12 months. Serum 1,25-dihydroxyvitamin D also increased significantly. Parathyroid function normalized. The median height Z-score was -2.2 (-2.7 to +0.4) at GH onset and -1.7 (-2.3 to +0.3) at 12 months. One patient showed a significant increase in radiographic rickets activity and 3 patients aggravation of lower limb deformity; the others showed no changes or improvement in these parameters. CONCLUSIONS: GH treatment improved serum phosphate and 1,25-dihydroxyvitamin D, normalized parathyroid function and improved longitudinal growth in XLH. It may however aggravate pre-existing skeletal deformities.

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 biopsy and densitometry findings in a child with Camurati-Engelmann disease.

Progressive diaphyseal dysplasia (MIM 131300), also known as Camurati-Engelmann disease (CED), is a rare autosomal dominant craniotubular dysplasia caused by mutations in the transforming growth factor beta1 (TGF-beta1) gene. Radiographs of the long bones of a 9-year-old boy presenting with waddling gait, muscular weakness, underweight, and severe skeletal pain showed symmetric diaphyseal cortical thickening pathognomonic for CED. The diagnosis was verified by detecting a mutation in exon 4 of the TGF-beta1 gene. Full body bone mineral densitometry studies performed before treatment with prednisolone were indicative for osteoporosis (Z-scores for the lumbar spine and femoral neck -2.3 and -3.2, respectively). A transiliac bone biopsy showed markedly reduced trabecular bone volume. Oral prednisolone was initiated, and subsequently, pamidronate infusions were commenced in an attempt to prevent progression of osteoporosis. To our knowledge, this is the first time bone biopsy and bone mineral densitometry studies have been performed and bisphosphonate treatment evaluated in a child with CED.

Skeletal dysplasia presenting as a neuromuscular disorder - report of three children.

Three pediatric patients were investigated because of suspected muscle disorder. They were clumsy with an awkward looking waddling gait and had increasing muscle weakness and pain in the legs. Serum CK-values, electroneuromyography (ENMG) and muscle biopsy were all normal. A post-traumatic X-ray of the ankle of one of them showed epiphyseal changes and his condition was diagnosed as Camurati-Engelmann disease. Because of similarities in the clinical presentation of these boys, bone changes were looked for in the two other patients and a diagnosis of multiple epiphyseal dysplasia was made. Skeletal dysplasia should be considered as a diagnostic alternative when a child presents with an unexplained muscle weakness accompanied with pain in the limbs. Specific treatment for bone dysplasias can alleviate symptoms and prevent fractures.

Interstitial 1q25.3-q31.3 deletion in a boy with mild manifestations.

We describe a 4-year-old boy with an accessory right thumb, short and broad toes, cryptorchidism, micrognathia, abnormally modeled ears, and delayed speech development. The chromosome analysis of patient's peripheral blood lymphocytes by conventional GTG banding demonstrated a small deletion in the long arm of chromosome 1. Confirmation and defined localization of the deleted segment to chromosomal bands 1q25.3-q31.3 was obtained by high resolution prometaphase analysis. Molecular studies, using a set of polymorphic chromosome 1q specific microsatellite markers, localized the deletion between the markers D1S2127 and D1S1727 on the paternally inherited chromosome 1. The maximum physical distance between these markers is approximately 21 Mb. The previously described two patients with 1q25-q31 deletions both had severe clinical manifestations, just as the other 10 patients with the proposed "intermediate 1q deletion syndrome," associated with 1q25-q32 deletions. Distinct from all these patients, the clinical picture of our patient is markedly milder, i.e., without growth retardation, microcephaly, or clear mental retardation.

Cervical spine in patients with diastrophic dysplasia--radiographic findings in 122 patients.

BACKGROUND: In previous studies, typical radiological findings in the cervical spine of patients with diastrophic dysplasia (DD) have been kyphosis, displacement of the vertebrae, spina bifida occulta (SBO), anterior hypoplasia of vertebrae C3-5, and hyperplasia and dysmorphism of the odontoid process. OBJECTIVES: To make a radiological analysis of the cervical spine in patients with DD. MATERIALS AND METHODS: The study comprised 122 patients (50 males, 72 females), with an average age of 19 years (range newborn-63 years). Follow-up was available on 62 patients (51%), for an average duration of 11 years. Cervical spine alignment was measured according to Cobb's method. The height (H) and depth (D) of the vertebral body and sagittal diameter (S) of the spinal canal were measured. H/D and S/D ratios were then calculated from the measurements. The shape of the vertebrae was assessed. Displacement and movement of cervical vertebrae in neutral and bending radiographs were measured. RESULTS. The average lordosis in the last radiograph was 17(degrees) (range 4 degrees -55(degrees)). Five (4%) patients had a cervical kyphosis with an average of 92(degrees) (range 10-165(degrees)) on their last radiograph. The H/D ratio increased slowly during growth and showed significant correlation with age. There was no growth spurt at puberty. The S/D ratio was fairly stable until 7-8 years of age, when it started to decline slowly. The percentage of vertebrae with a flat vertebral body and narrow spinal canal value tended to increase with age. Vertebral hypoplasia and displacement between vertebrae were most common in the mid-cervical region and resolved spontaneously with age. Degenerative changes seemed to increase with age and were already visible during the second decade of life. SBO was noted in 79% of patients. CONCLUSIONS: The most common alignment in the cervical spine is lordosis in adulthood. The vertebral bodies are flattened and the spinal canal is narrowed. Vertebral body hypoplasia and displacement usually resolve spontaneously during growth. Degenerative changes in the cervical spine are common, but vertebral anomalies are rare. Prevalence of SBO is high.

Growth after renal transplantation in infancy or early childhood.

Forty-one children <5 years of age at kidney transplantation (TX) were investigated for growth, bone age, and renal function up to 7 years ( n=26) after TX. All children received triple immunosuppression, including alternate-day corticosteroid treatment. Catch-up growth was seen in 81% of 30 children without growth hormone (GH) treatment. Children <2 years of age without GH had a mean height standard deviation score (hSDS) of -1.1+/-0.8 at TX and -1.1+/-0.5 at 7 years; children between 2 and 5 years improved their hSDS from -1.9+/-0.9 to -0.4+/-0.8 ( P<0.0001). The hSDS at TX correlated inversely with the DeltahSDS from TX to 7 years ( r=-0.80, P=0.0002). Glomerular filtrations rate (GFR) at 5 years post TX correlated with the subsequent growth rate from 5 to 7 years TX ( r=0.58, P=0.01). Catch-up growth was seen in all 11 children receiving GH. Their mean hSDS improved from -2.5+/-0.9 to -1.1+/-0.9 ( P<0.0001). In the majority of children receiving a kidney graft in early life, triple immunosuppression with alternate-day steroids can ensure catch-up growth. In children <5 years of age at TX, growth is predicted better by the degree of stunting than by age.