A loss-of-function mutation in NaPi-IIa and renal Fanconi's syndrome

We describe two siblings from a consanguineous family with autosomal recessive Fanconi's syndrome and hypophosphatemic rickets. Genetic analysis revealed a homozygous in-frame duplication of 21 bp in SLC34A1, which encodes the renal sodium-inorganic phosphate cotransporter NaPi-IIa, as the causative mutation. Functional studies in Xenopus laevis oocytes and in opossum kidney cells indicated complete loss of function of the mutant NaPi-IIa, resulting from failure of the transporter to reach the plasma membrane. These findings show that disruption of the human NaPi-IIa profoundly impairs overall renal phosphate reabsorption and proximal-tubule function and provide evidence of the critical role of NaPi-IIa in human renal phosphate handling.

Detection and incidence of anomalies associated with hypospadias

Hypospadias has been associated with synchronous congenital anomalies, especially in the urogenital system, and routine screening of patients with hypospadias has been advocated. In recent years, ultrasound (US) has replaced intravenous pyelography (IVP) as the primary screening test for urological deformities, yet there has never been a study of the relative diagnostic efficacy of the two tests in these patients. In this study, we assessed the incidence of urogenital and extraurogenital congenital anomalies in our hypospadias patients that were noted during physical examination and/or laboratory and imaging screening, and evaluated the efficacy of our changing routine screening protocols. We conducted a retrospective analysis of the charts of all hypospadias patients seen at Assaf Harofeh Medical Center. One hundred and sixty-three hypospadias patients fulfilled the documentation criteria we set for this study. We found a high incidence of urogenital and extraurogenital anomalies associated with hypospadias and noted a previously unreported increased incidence of various forms of facial dysmorphism. Additionally, we noted that the accepted concept that US or IVP alone were satisfactory screening tools for asymptomatic low-grade hypospadias patients is probably incorrect. Based on our findings, we recommend that initial screening of all asymptomatic hypospadias patients include US, cystogram, urinalysis, and urine culture.

SLC34A3 mutations in patients with hereditary hypophosphatemic rickets with hypercalciuria predict a key role for the sodium-phosphate cotransporter NaPi-IIc in maintaining phosphate homeostasis

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare disorder of autosomal recessive inheritance that was first described in a large consanguineous Bedouin kindred. HHRH is characterized by the presence of hypophosphatemia secondary to renal phosphate wasting, radiographic and/or histological evidence of rickets, limb deformities, muscle weakness, and bone pain. HHRH is distinct from other forms of hypophosphatemic rickets in that affected individuals present with hypercalciuria due to increased serum 1,25-dihydroxyvitamin D levels and increased intestinal calcium absorption. We performed a genomewide linkage scan combined with homozygosity mapping, using genomic DNA from a large consanguineous Bedouin kindred that included 10 patients who received the diagnosis of HHRH. The disease mapped to a 1.6-Mbp region on chromosome 9q34, which contains SLC34A3, the gene encoding the renal sodium-phosphate cotransporter NaP(i)-IIc. Nucleotide sequence analysis revealed a homozygous single-nucleotide deletion (c.228delC) in this candidate gene in all individuals affected by HHRH. This mutation is predicted to truncate the NaP(i)-IIc protein in the first membrane-spanning domain and thus likely results in a complete loss of function of this protein in individuals homozygous for c.228delC. In addition, compound heterozygous missense and deletion mutations were found in three additional unrelated HHRH kindreds, which supports the conclusion that this disease is caused by SLC34A3 mutations affecting both alleles. Individuals of the investigated kindreds who were heterozygous for a SLC34A3 mutation frequently showed hypercalciuria, often in association with mild hypophosphatemia and/or elevations in 1,25-dihydroxyvitamin D levels. We conclude that NaP(i)-IIc has a key role in the regulation of phosphate homeostasis.

Hereditary hypophosphatemic rickets with hypercalciuria: report of a new kindred

We report a new kindred of hereditary hypophosphatemic rickets with hypercalciuria. The symptomatic child and several relatives had increased renal phosphate clearance leading to hypophosphatemia, hyperabsorptive hypercalciuria, low PTH and increased 1,25-(OH)2D serum level. However, association with vitamin D deficiency and normal urinary excretion of cyclic AMP might suggest another tubular defect in phosphate transport.

Hereditary hypophosphatemic rickets with hypercalciuria is not caused by mutations in the Na/Pi cotransporter NPT2 gene

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH), a renal phosphate (Pi) wasting disease first described in an extended Bedouin kindred, is characterized by hypophosphatemia, elevated serum 1,25-dihydroxyvitamin D levels, hypercalciuria, rickets, and osteomalacia. Correction of all abnormalities, except for renal Pi wasting, can be achieved by oral Pi supplementation. These findings and the demonstration that mice that are homozygous for the disrupted Na/Pi cotransporter gene Npt2 exhibit many of the biochemical features of HHRH suggested that mutations in the human orthologue NPT2 might be responsible for HHRH. The NPT2 gene in affected individuals from the Bedouin kindred and four small families was screened for mutations to test this hypothesis. No putative disease-causing mutation was found. Two single nucleotide polymorphisms (SNP), a silent substitution in exon 7 and a nucleotide substitution in intron 4, were identified, and neither consistently segregated with HHRH in the Bedouin kindred. Linkage analysis indicated that the two NPT2 intragenic SNP as well as five microsatellite markers in the NPT2 gene region were not linked to HHRH in the Bedouin kindred. Therefore, this is evidence to exclude NPT2 as a candidate gene for HHRH in the families that were studied.

Therapy-resistant seizures in pseudohypoparathyroidism. A case report

A 30 year-old, mentally retarded female presented with uncontrolled seizures. The diagnosis of pseudohypoparathyroidism was established on grounds of clinical, laboratory and radiological evaluation. Despite normalization of serum calcium levels with vitamin D treatment, the patient continued to suffer from frequent convulsions. The possible pathogenesis of the therapy-resistant seizures and the therapeutic approach are discussed.

The Weismann-Netter, Stuhl syndrome: a rare pediatric skeletal dysplasia

A 5-year-old girl presented with lower limb deformities, delayed ambulation, short stature, facial dysmorphism and scoliosis. Radiologic examination showed severe anterior and external bowing of the femurs and anterior and internal bowing of the tibia and fibula, with posterior and medial cortical thickening. Square iliac wings, horizontal sacrum and low-set L5 were also seen. The diagnosis of Weismann-Netter, Stuhl syndrome was established with the exclusion of abnormalities in mineral and vitamin D metabolism. This rare skeletal dysplasia should be included in the radiologic differential diagnosis of congenital deformities of the lower extremities.

Maffucci's syndrome--the result of neural abnormalities? Evidence of mitogenic neurotransmitters present in enchondromas and soft tissue hemangiomas

BACKGROUND

Maffucci's syndrome (MS) is distinguished by the enigmatic association of benign cartilaginous bone tumors and soft tissue hemangiomas.

METHODS

This study was conducted to define the distribution of nerves and neuropeptides around these tumors. Results were measured by quantitative image analysis of immunohistochemical staining. Four types of tissues were compared: connective tissues around normal muscles, solitary hemangiomas, MS hemangiomas, and MS enchondromas (the last two from a single patient).

RESULTS

The number of nerves was found to be quadrupled in both types of hemangiomas as compared to normal connective tissue. A unique feature of MS tissues is the presence of an increased number of nerve fibers not only in the lesions but also in histologically normal margins of resection surrounding the lesions. Furthermore, hemangiomas of both types were found to contain a significantly higher number of calcitonin gene-related peptide-, substance P-, and methionine enkephalin-positive fibers than did normal muscle or its related fibroconnective tissue. These neuropeptides are mitogens, and their presence stimulates the growth of the abnormal blood vessels. Enchondroma fragments from an MS patient contained numerous methionine enkephalin-positive nerves. This neuropeptide is known to act as a growth factor in cartilage proliferation.

CONCLUSIONS

A neural abnormality of the neuropeptidergic nervous system seems to relate to the abnormal tumors seen in MS.

Benign fibroepithelial polyps of the ureter and renal pelvis in childhood. Two case reports

Benign fibroepithelial polyps of the ureter and renal pelvis are extremely rare in children. Two cases are presented and the clinical and surgical aspects of diagnosis and treatment are discussed.

Hyperoxaluria is not a cause of nephrocalcinosis in phosphate-treated patients with hereditary hypophosphatemic rickets

The treatment of X-linked hypophosphatemia (XLH) consists of phosphate and vitamin D3 derivatives. Transient hypercalciuria and hypercalcemia are well-known signs of vitamin D intoxication. Despite urinary calcium excretion control, the danger of nephrocalcinosis in treated patients has been emphasized. It has recently been suggested that hyperoxaluria might be a causative factor of nephrocalcinosis other than calcium in phosphate-treated XLH patients. We measured urinary oxalate and phosphate excretion in 12 patients with the syndrome of hereditary hypophosphatemic rickets with hypercalciuria (HHRH) receiving only oral phosphates and in 5 XLH patients receiving both oral phosphates and vitamin D. No correlation was found between the dosage of phosphate supplements or urinary phosphate excretion and urinary oxalate excretion, in either group of patients. Nephrocalcinosis, presenting as hyperechogenicity of the medullary pyramids, was found in 2 of the 5 XLH patients and only in 2 HHRH patients who had been treated with excessive doses of vitamin D2 and calcium, prior to the true diagnosis being established. We conclude: (1) hyperoxaluria is not a cause of nephrocalcinosis in phosphate-treated patients with hereditary hypophosphatemic rickets; (2) prolonged phosphate treatment alone does not induce nephrocalcinosis in HHRH patients, and (3) we believe that in XLH patients, nephrocalcinosis is essentially due to vitamin D overdosage at some stage, or noncompliance in phosphate intake, leading to repeated undetected hypercalciuric periods.

A new kindred with hereditary hypophosphatemic rickets with hypercalciuria: implications for correct diagnosis and treatment

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a new autosomal form of hypophosphatemic rickets, recently described. This disease is characterized, and differs from other forms of hereditary hypophosphatemic rickets and/or osteomalacia by increased serum levels of 1,25-dihydroxyvitamin D, hypercalciuria and complete remission of the disease on phosphate therapy alone. However, only another probable Israeli kindred, and seemingly a few sporadic cases from Europe, North America and Japan have been reported in the literature. We describe here a new kindred of Jewish Yemenite origin (unrelated to other Israeli families) with typical HHRH. Two additional members of this family suffer from a milder asymptomatic form of the disease, which presents as absorptive hypercalciuria without signs or symptoms of bone disease. It seems to us that HHRH is underdiagnosed, due to its similarity to other hypophosphatemic syndromes in clinical, radiological and most biochemical parameters. Therefore, it is recommended that urinary calcium excretion and serum 1,25-dihydroxyvitamin D concentrations be measured in every patient with hypophosphatemic rickets/and or osteomalacia before the initiation of any therapy. The correct diagnosis of HHRN is of immense therapeutic implications. Phosphate therapy alone could cause a complete remission in HHRH, while the addition of active vitamin D metabolites, as is recommended in hypophosphatemic vitamin D resistant rickets, could cause deterioration in the patient's condition.

Osteomalacia in hereditary hypophosphatemic rickets with hypercalciuria: a correlative clinical-histomorphometric study

We characterized the bone disease of transilial biopsy specimens from children with hereditary hypophosphatemic rickets with hypercalciuria (HHRH) and genetically related asymptomatic hypercalciuric subjects. All HHRH patients showed irregular mineralization fronts, markedly elevated osteoid surface and seam width, increased number of osteoid lamellae, and prolonged mineralization lag time. These findings are consistent with a mineralization defect and indicate unambiguously that the bone disease in HHRH is osteomalacia. The only abnormality seen in the asymptomatic hypercalciuric subjects was slightly extended osteoid surface. Parametric and nonparametric statistical analyses performed on a pooled sample of HHRH patients and asymptomatic hypercalciuric subjects revealed a very high inverse correlation and a tight linear relationship between serum phosphorus and osteoid parameters. Serum 1,25-dihydroxyvitamin D, which is low in other forms of hereditary hypophosphatemia and osteomalacia, is elevated in HHRH and correlated positively with osteoid parameters and the mineralization lag time. Serum alkaline phosphatase showed similar relationships. These results as well as the clinical, biochemical, and radiological remission of bone disease consequent to phosphate therapy strongly suggest that in HHRH 1) hypophosphatemia alone is sufficient to cause osteomalacia; and 2) the elevation of 1,25-dihydroxyvitamin D reflects the degree of the primary renal phosphate leak, but is not involved in the pathogenesis of the bone disease.

Linear growth in patients with hypophosphatemic vitamin D-resistant rickets: influence of treatment regimen and parental height

The effects of different treatment regimens and the influence of parental height on the statural growth of 40 patients with hereditary vitamin D-resistant hypophosphatemic rickets were investigated. Three treatment regimens, each with oral phosphate, were used: vitamin D (0.5 to 2 mg/day), calcidiol (50 to 200 micrograms/day), and 1 alpha-hydroxyvitamin D3 (1 to 3 micrograms/day). Mean duration of follow-up was 9.5 +/- 5.1 years. The results show that (1) there was no acceleration of growth before puberty for the majority of children treated with vitamin D (12/16) or calcidiol (13/15), whereas 1 alpha-hydroxyvitamin D3 promoted catch-up growth in 10 of 16 patients; (2) height gain during puberty was normal, irrespective of the treatment; (3) most vitamin D-treated male and female subjects and calcidiol-treated male subjects had short adult stature, but the majority (75%) of the 1 alpha-hydroxyvitamin D3-treated groups had normal stature; (4) parental stature had little influence on the adult height of male subjects, but that of affected girls was positively correlated (p less than 0.002) with mid-parental height. These results demonstrate that 1 alpha-hydroxyvitamin D3 is superior to vitamin D or calcidiol for improvement of stature of patients with hypophosphatemic vitamin D-resistant rickets, and indicate the importance of parental height in determining the adult height of affected girls.

Spondyloepiphyseal dysplasia associated with progressive arthropathy. An unusual disorder mimicking juvenile rheumatoid arthritis

A family is presented with three affected siblings suffering from a rare form of spondyloepiphyseal dysplasia with progressive arthropathy affecting most joints of the body except for the craniofacial skeleton. This syndrome, probably of autosomal recessive inheritance, clinically presents diffuse and chronic joint involvement and should be differentiated from juvenile rheumatoid arthritis and other rheumatic disorders.

Hypercalciuria as a cause of persistent or recurrent haematuria

Of 91 children with idiopathic persistent or recurrent haematuria, eight also had hypercalciuria. This was transient in three and persistent in five. Persistent hypercalciuria was a rare cause of microscopic haematuria (two of 80), but common in association with gross haematuria (three of 11).

Effect of levamisole on chemotaxis of granulocytes from uremic patients

Uremic granulocyte chemotaxis was assessed in the presence of four different concentrations of levamisole. Chemotactic responsiveness of uremic granulocytes was significantly decreased compared to normal, both in the absence of levamisole and with all levamisole concentrations tested. However, with 10(-3) and 10(-4) M levamisole concentrations, uremic granulocyte chemotaxis was similar to that of normal granulocytes without levamisole. Defective chemotactic activity of granulocytes may play a role in the increased susceptibility of uremic patients to infections. Pharmacological correction of this defect may improve the patients' ability to cope with infections.

1,25-Dihydroxyvitamin D-induced suppressor cells in uremic versus normal lymphocytes

1,25-Dihydroxyvitamin D3 (DHD) has been shown to suppress mitogen-induced blast transformation. This inhibition is abolished by prior elimination of adherent cells. Chronic renal failure is an immunodeficiency state on the one hand and is associated with abnormalities in vitamin D metabolism on the other. The effect of DHD on the induction of suppressor cells in uremic vs. normal peripheral blood mononuclear cells was investigated. Study groups included 16 chronically uremic patients and 16 age- and sex-matched controls. DHD induced suppressor cell activity in normal lymphocytes. However, no suppressor cell activity was observed in lymphocytes from the uremic patients preincubated with DHD. The origin of the responder cells (normal or uremic) did not affect the outcome. The results would suggest that monocyte-adherent suppressor cells from uremic subjects are either incapable of binding DHD or fail to mount a normal post-receptor intracellular chain of events culminating in suppressor activity.

"Idiopathic" hypercalciuria and hereditary hypophosphatemic rickets. Two phenotypical expressions of a common genetic defect

Among 59 closely related members of one Bedouin tribe, we identified 9 who had the characteristic features of hereditary hypophosphatemic rickets with hypercalciuria (HHRH). We found "idiopathic" hypercalciuria in 21 of the 50 asymptomatic members. The biochemical abnormalities observed in these 21 subjects were qualitatively similar to those in the 9 with HHRH, but were quantitatively milder. The urinary calcium concentration was 0.43 +/- 0.14 mg per milligram of creatinine (mean +/- SD) in the patients with HHRH, 0.34 +/- 0.07 in the subjects with idiopathic hypercalciuria, and 0.14 +/- 0.05 in normal subjects from the same tribe. Tubular reabsorption of phosphorus and serum phosphorus concentrations were 3.0 and 4.3 SD units below the age-related mean, respectively, in HHRH, and 1.1 SD units below the normal mean for both variables in idiopathic hypercalciuria. Mean serum levels of 1,25-dihydroxyvitamin D (1,25-(OH)2D) were 303 pg per milliliter in HHRH and 145 pg per milliliter in idiopathic hypercalciuria (upper normal limit, 110). We conclude that the subjects with hypercalciuria and the patients with HHRH shared a hereditary renal phosphate leak that led to hypophosphatemia, elevated serum concentrations of 1,25-(OH)2D, increased intestinal calcium absorption, and hypercalciuria. The magnitude of the hypophosphatemia, which regulates 1,25-(OH)2D levels, appears to determine which subjects will have hypercalciuria alone and which will also have bone disease.

Pneumaturia: need for diagnostic alertness

Pneumaturia, an air-filled urinary bladder with or without passage of gas in the urine, is a rare phenomenon in the general population, but is more frequent in defined high-risk subgroups. Relevant symptomatology may be hardly noticeable for a relatively long period; however, the outcome may be serious and sometimes fatal. We present three such cases and discuss diagnostic and therapeutic aspects.

Induction of suppressor cells in normal lymphocytes by uremic serum

Sera of patients on chronic hemodialysis induced suppressor cell activity (SCA) in normal peripheral blood mononuclear cells, which significantly impaired blastogenic response to PHA. This SCA is statistically not different from Con A induced SCA. Both SCAs are however additive. Speculations concerning the modes of action of this induced SCA are discussed.

Direct measurement of TP/GFR: a simple and reliable parameter of renal phosphate handling

As the Walton-Bijvoet nomogram for estimating renal phosphate (P) threshold (TmP/GFR) is not applicable to children of all ages, we sought an alternative method for measuring renal handling of P. Recognizing that the nomogram represents an indirect correlation between TmP/GFR and TP/GFR under fasting conditions, we examined this directly in 26 children. An excellent correlation was found, expressed as TmP/GFR = (fasting TP/GFR X 1.1) -0.3 (r = 0.95). The regression line in adults, expressed as TmP/GFR = (fasting TP/GFR X 1.4) -0.9 (calculated from published studies) is markedly different at the higher values typical for children. Since no advantage could be seen in the use of a mathematically derived TmP, we investigated the direct use of measured TP/GFR (tubular P reabsorption per 100 ml glomerular filtrate) as a measure of renal P handling in clinical practice. No differences were found between morning fasting and nonfasting values. Measurements in 151 healthy subjects aged 3 days to 53 years established normal values in relation to age. The use of this parameter in patients is shown to accurately reflect defects and changes in renal P handling. We believe it to be the preferred parameter because it represents a directly measured physiologic function applicable to all age-groups.

Hereditary hypophosphatemic rickets with hypercalciuria

We studied a new hereditary syndrome of hypophosphatemic rickets and hypercalciuria in six affected members of one kindred. In all patients, the manifestations of disease began in early childhood. The characteristic features are rickets, short stature, increased renal phosphate clearance (the ratio between the maximal tubular reabsorption rate for phosphorus and the glomerular filtration rate [TmP/GFR] is 2 to 4 S.D. below the age-related mean), hypercalciuria (8.6 mg of urinary calcium per kilogram of body weight per 24 hours vs. the upper normal value of 4.0), normal serum calcium levels, increased gastrointestinal absorption of calcium and phosphorus, an elevated serum concentration of 1,25-dihydroxyvitamin D (390 +/- 99 pg per milliliter vs. the upper normal value of 110), and suppressed parathyroid function (an immunoreactive parathyroid hormone level of 0.33 +/- 0.1 ng per milliliter and a cyclic AMP level of 1.39 +/- 0.12 nmol per deciliter of glomerular filtrate vs. the lower normal values of 0.3 and 1.5, respectively). Long-term phosphate supplementation as the sole therapy resulted in reversal of all clinical and biochemical abnormalities except the decreased TmP/GFR. We propose that the pivotal defect in this syndrome is a renal phosphate leak resulting in hypophosphatemia with an appropriate elevation of 1,25-dihydroxyvitamin D levels, which causes increased calcium absorption, parathyroid suppression, and hypercalciuria. This syndrome may represent one end of a spectrum of hereditary absorptive hypercalciuria. Our observations support the importance of phosphate as a mediator in controlling 1,25-dihydroxyvitamin D production in human beings.

Hypercalciuric rickets: metabolic studies and pathophysiological considerations

Extensive metabolic studies were performed in a 14-year-old boy suffering from the rare clinical entity known as childhood idiopathic hypercalciuria associated with dwarfism, renal tubular abnormalities and bone lesions. The salient features were: hyperphosphaturia with hypophosphatemia, hypercalciuria with normocalcemia, elevated serum 1,25-dihydroxycholecalciferol[1,25(OH)2D3] levels, marked intestinal hyperabsorption of calcium and phosphorus, with low serum parathyroid hormone (PTH) and urinary adenosine 3':5'-cyclic monophosphate (c-AMP). Bone biopsy confirmed the clinical and radiological diagnosis of rickets. It appears that the following pathophysiological sequence is operating: primary renal phosphate leak with hypophosphatemia, increased 1,25(OH)2D3 synthesis, enhanced intestinal calcium absorption which in turn inhibits release of PTH and c-AMP. Hypercalciuria is seen to be secondary to both avid intestinal calcium absorption and depressed PTH activity, and rickets the result of phosphate depletion. Treatment with oral phosphorus only resulted in an acceleration of growth rate, cure of rickets, and return of urinary calcium excretion to normal values.

Multiple exostoses-mental retardation syndrome. A case report and review of the literature

A girl seven years ten months of age with multiple exostoses-mental retardation (MEMR) syndrome was treated by bilateral supracondylar osteotomies at the age of six years 11 months for correction of severe genu valgum. The case is the 14th to be described in the English-language literature and seems to be the first on record in which the deformity was corrected by surgery. Typical findings in this syndrome include unusual facial features with bulbous nose, sparse scalp hair, large ears, microcephaly, mental retardation, cone-shaped epiphyses of the digital phalanges, and multiple exostoses. Each of these features may also appear in other constitutional and genetic disorders, and only their combination points to a definite diagnosis of MEMR syndrome. Other features, e.g., joint laxity and loose skin, are transient and may cause some confusion in diagnosis, sometimes leading to a mistaken diagnosis of cerebral palsy or Ehlers-Danlos syndrome. Thus, care must be taken in consecutive examinations to seek and identify each of the above mentioned typical features of the disorder.

Pathophysiologic studies in idiopathic hypercalciuria presenting in childhood

Idiopathic hypercalciuria (IH) was diagnosed in 11 children aged 5 3/12 to 10 6/12. Eight patients investigated 1-12 years later still had hypercalciuria. When compared to a control group of 10 healthy children, 5 patients demonstrated an excessive rise in urinary Ca excretion following an oral Ca load. These patients also demonstrated low urinary cAMP, normal serum iPTH and high normal iTCT levels. The remaining 3 patients responded normally to Ca loading, but otherwise showed similar metabolic findings as the above group. These findings suggest a hyperabsorptive mechanism for all our patients. The finding of relatively low values for TmP/GFR in most IH patients further suggests that here, as in many adult patients, this may be the primary pathogenic mechanism, causing low serum P, increased synthesis of 1,25 dihydroxyvitamin D and, thus, absorption of Ca. We believe this represents a physiologic variant state and not a disease state.

Renal abnormalities in the Bardet-Biedl syndrome

Four cases of BARDET-Biedl syndrome (BBS) are described which all suffer from renal abnormalities. Polyuria or polydipsia with impairment of renal concentration capacity were the earliest signs of renal dysfunction. Renal insufficiency developed in 3 cases and hypertension in two. Urographic abnormalities were demonstrated in all patients. The most remarkable features were cystic spaces communicating with the calices and lobulation of kidney. Caliceal clubbing and caliectasis surrounded by narrowed, unscarred parenchyma were frequent findings. Previous investigators reported various renal histological pictures in BBS. We found tubulo- interstitial lesions in all cases. Features of dysplasia and cystic formations were less frequent. Mesangial proliferation was not noted. Ultra-structural changes in the glomerular basement membrane were not observed in this study. Thirty-one of 32 recently reported cases of BBS included renal lesions which are the major cause of death. It is therefore suggested that renal abnormalities are accepted as the cardinal feature of this syndrome.

A practical approach to the treatment of burn shock in childhood

A simple method of evaluating and treating burn shock has been used with very good results and low mortality. The amounts of fluids given in a specific time and the type of fluids given are dependent upon the evaluation of a few simple observations. We believe that shock is a treatable condition and that 'shock kidney' is preventable. We stress the difficulty of trying to compare the results of two different burn units.

Vitamin D resistant rickets with alopecia: a form of end organ resistance to 1,25 dihydroxy vitamin D

A 4-year-old girl presented with severe clinical and radiological rickets, and alopecia since the age of 1 year. Laboratory studies revealed: hypocalcaemia, hypophosphataemia, secondary hyperparathyroidism, abnormally low intestinal calcium absorption, and markedly elevated circulating 1,25(OH)2D3 levels. A normal calcaemic response to parathyroid extract was obtained. Treatment attempts with vitamin D2, 1 alpha (OH)D3 and 1,25(OH)2D3 were totally ineffective. Intestinal resistance to the action of 1,25(OH)2D3 appeared well established in this case. Refractoriness of bone to this hormone seems less certain. From this new entity of 'Vitamin D resistant rickets due to end organ unresponsiveness', six cases have been hitherto reported in the literature. However, only two have enough resemblance to our case, to constitute a distinct and well defined nosologic subunit. The molecular basis of this disorder(s) remains to be elucidated.

[Familial form of idiopathic hypercalciuria with nanism, bone and renal involvement in children]

A brother and a sister are reported, demonstrating the severe form of childhood idiopathic hypercalciuria associated with dwarfism, renal defects and bone lesions (rickets and osteoporosis). The family are Israeli Beduins from a small village with a highly inbred population. The parents who are first cousins, and the remaining 6 siblings are not affected. This suggests an autosomal recessive form of transmission for the trait.

Mental retardation with 45 chromosomes 45,XX,--5,--14,+der(5) t(5,14)(p15;q13) mat due to familial balanced reciprocal translocation

A girl with severe mental retardation and odd facies and some features of the cri-duchat syndrome was found to have only 45 chromosomes. Her karyotype was 45,XX, -5, -14,+der(5) t(5,14)(p15;q13) mat. Her mother and her two sisters were found to be balanced reciprocal translocation carriers having 46 chromosomes, one of which was a very small (14pter leads to 14q13::5p15leads to 5pter) that was missing in the proposita.

[Salt-losing syndrome in newborn infants with hyperaldosteronism. Presenting a sensitivity to mineralocorticoids. Pseudohypoaldosteronism]

A case of salt-loosing syndrome in infancy with hyperaldosteronism is reported. This patient was given high doses of 9 alpha Fluorocortisol (0.1 mg/kg/24 h), together with salt supplements. This treatment corrected the abnormality, while higher doses of salt supplements without such large amounts of Flurocortisol were ineffective.

Trisomy 13 mosaic presenting as cleft lip and palate

A mosaic trisomy 13 presenting as a case of cleft lip and palate in the newborn is described. However, when the child was admitted to hospital at the age of 6 weeks because of failure to gain weight and a malformation of the great vessels was demonstrated, cytogenetic studies were carried out. The diagnosis of mosaic trisomy 13 (90% normal, 10% trisomic) was established from a leukocyte culture. Since, occasionally, mosaic trisomy 13 may mimic cleft lip and palate in the newborn, cytogenetic studies are indicated in the presence of any additional anomaly.

The management of benign renal tumors of infancy. Case report of a congenital mesoblastic nephroma (leiomyomatous hamartoma)

A case of a benign renal tumor found in an infant of 11/2 months is reported. Its clinical, radiological and operative findings were similar to those described previously as Wilms' tumors. Only pathological examination revealed its benignancy. In view of the occurrence of benign congenital mesoblastic nephroma which is evidently not rare in infancy, and because of the side effects of adjuvant cytotoxic and X-ray therapy, the authors feel that the immediate therapeutic approach to a solid intrarenal tumor in infancy should be surgical only. Further therapy should depend on pathological findings.