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Background: A radiologic diagnosis of hypochondroplasia is hampered by the absence of age-dependent radiologic criteria, particularly in the neonatal period., Objective: To establish radiologic criteria and scoring system for identifying neonates with fibroblast growth factor receptor 3 (FGFR3)-associated hypochondroplasia., Materials and Methods: This retrospective study included 7 hypochondroplastic neonates and 30 controls. All subjects underwent radiologic examination within 28 days after birth. We evaluated parameters reflecting the presence of (1) short ilia, (2) squared ilia, (3) short greater sciatic notch, (4) horizontal acetabula, (5) short femora, (6) broad femora, (7) metaphyseal flaring, (8) lumbosacral interpedicular distance narrowing and (9) ovoid radiolucency of the proximal femora., Results: Only parameters 1, 3, 4, 5 and 6 were statistically different between the two groups. Parameters 3, 5 and 6 did not overlap between the groups, while parameters 1 and 4 did. Based on these results, we propose a scoring system for hypochondroplasia. Two major criteria (parameters 3 and 6) were assigned scores of 2, whereas 4 minor criteria (parameters 1, 4, 5 and 9) were assigned scores of 1. All neonates with hypochondroplasia in our material scored ≥6., Conclusion: Our set of diagnostic radiologic criteria might be useful for early identification of hypochondroplastic neonates.

Objectives: The aim of the study was to introduce a novel three-dimensional (3D) method to quantify the relative amount of different tissue components in bone substitute-treated defects by means of integration of confocal laser imaging into micro-computed tomography (μCT) analysis., Materials and Methods: One standardized semisaddle intraosseous defect was prepared in the mandibles of six minipigs and scanned by an optical scanner to capture the surface of the fresh defect in a 3D manner. Subsequently, all the defects were filled with a biphasic calcium phosphate material. The animals were divided into two groups of three animals each, which were allowed to heal for 3 and 8 weeks, respectively. μCT analysis followed the two healing periods and was performed on all defect locations. The data from optical scanning and μCT were used for three-dimensional evaluation of bone formation, nonmineralized tissue ratio, and graft degradation. The integration of confocal laser scanning into μCT analysis through a superimposition imaging procedure was conducted using the software Amira (Mercury Computer Systems, Chelmsford, MA, USA)., Results: The feasibility of combining the confocal imaging into μCT data with regard to obtaining accurate 3D quantification was demonstrated. The amount of tissue components was identified and quantified in all the investigated samples. Quantitative analysis demonstrated that a significant increase in the amount of bone filling the defect was observed in vivo (p < 0.02) while a significant decrease in the amount of nonmineralized tissue occurred (p < 0.04). No difference in the amount of residual grafting material was detected between 3 and 8 weeks in vivo (p > 0.38)., Conclusions: The combination of confocal imaging and micro-computed tomography techniques allows for analysis of different tissue types over time in vivo. This method has revealed to be a feasible alternative to current bone regeneration quantification methods., Clinical Relevance: Assessment of bone formation in a large animal model is a key step in assessing the performance of new bone substitute materials. Reliable and accurate methods are needed for the analysis of the regenerative potential of new materials.

Radiology plays a key part in the investigation of non-accidental injury. Many normal variants and artefacts can simulate an abnormality associated with non-accidental injury. It is essential that radiologists reporting skeletal surveys in cases of suspected child abuse are aware of these. We present a pictorial essay to aid the reporting radiologist in the differentiation between normal variants or artefacts and true traumatic injury. We show plain film examples of potential pitfalls throughout the body.

Objectives: Previously, the use of enamel matrix derivative (EMD) in combination with a natural bone mineral (NBM) was able to stimulate periodontal ligament cell and osteoblast proliferation and differentiation. Despite widespread use of EMD for periodontal applications, the effects of EMD on bone regeneration are not well understood. The aim of the present study was to test the ability of EMD on bone regeneration in a rat femur defect model in combination with NBM., Materials and Methods: Twenty-seven rats were treated with either NBM or NBM + EMD and assigned to histological analysis at 2, 4, and 8 weeks. Defect morphology and mineralized bone were assessed by μCT. For descriptive histology, hematoxylin and eosin staining and Safranin O staining were performed., Results: Significantly more newly formed trabecular bone was observed at 4 weeks around the NBM particles precoated with EMD when compared with NBM particles alone. The drilled control group, in contrast, achieved minimal bone regeneration at all three time points (P < 0.05)., Conclusions: The present results may suggest that EMD has the ability to enhance the speed of new bone formation when combined with NBM particles in rat osseous defects., Clinical Relevance: These findings may provide additional clinical support for the combination of EMD with bone graft for the repair of osseous and periodontal intrabony defects.

Background: Thanatophoric dysplasia (TD) and hypochondroplasia are both caused by FGFR3 (fibroblast growth factor receptor 3) gene mutations. Temporal lobe dysplasia has been well described in thanatophoric dysplasia; however, only a couple of anecdotal cases of temporal lobe dysplasia in hypochondroplasia have been described., Objective: To define temporal lobe abnormalities in patients with hypochondroplasia, given that they share the same genetic mutation., Materials and Methods: We identified brain imaging studies of nine children with hypochondroplasia. The temporal lobes were assessed on CT and MRI for size and configuration of the temporal horn and aberrant sulcation of the inferior surface of the temporal lobe., Results: All children had a triangular-shape temporal horn and deep transverse fissures of the inferior temporal lobe surface. Neuroimaging in our cohort revealed enlarged temporal lobes and oversulcation of the mesial temporal and occipital lobes, with abnormal inferomedial orientation of these redundant gyri. Hippocampal dysplasia was also universal., Conclusion: We confirmed frequent inferomesial temporal and occipital lobe abnormalities in our cohort of children with hypochondroplasia. Murine models with mutant fgfr3 display increased neuroprogenitor proliferation, cortical thickness and surface area in the temporo-occipital cortex. This is thought to result in excessive convolution and likely explains the imaging findings in this patient cohort. (Note that fgfr3 is the same genetic mutation in mice as FGFR3 is in humans.).

Background: Progeria is a rare segmental premature aging disease with significant skeletal abnormalities. Defining the full scope of radiologic abnormalities requires examination of a large proportion of the world's progeria population (estimated at 1 in 4 million). There has been no comprehensive prospective study describing the skeletal abnormalities associated with progeria., Objective: To define characteristic radiographic features of this syndrome., Materials and Methods: Thirty-nine children with classic progeria, ages 2-17 years, from 29 countries were studied at a single site. Comprehensive radiographic imaging studies were performed., Results: Sample included 23 girls and 16 boys-the largest number of patients with progeria evaluated prospectively to date. Eight new and two little known progeria-associated radiologic findings were identified (frequencies of 3-36%). Additionally, 23 commonly reported findings were evaluated. Of these, 2 were not encountered and 21 were present and ranked according to their frequency. Nine abnormalities were associated with increasing patient age (P = 0.02-0.0001)., Conclusion: This study considerably expands the radiographic morphological spectrum of progeria. A better understanding of the radiologic abnormalities associated with progeria and improved understanding of the biology of progerin (the molecule responsible for this disease), will improve our ability to treat the spectrum of bony abnormalities.

The dwg and dwg (Bayer) are allelic mutations of the mouse that are characterized by dwarfism, cataracts, and coat color change in homozygotes. The Ggt1 gene encodes gamma-glutamyltransferase 1 (GGT1), an extracellular membrane-bound enzyme that is critical for glutathione homeostasis. Both the dwg locus and Ggt1 gene are localized on mouse chromosome 10, and the phenotypes of GGT1-deficient mice with targeted disruption of the Ggt1 gene show remarkable similarities with those of dwg/dwg and dwg (Bayer)/dwg (Bayer) mice. This evidence led us to hypothesize that the Ggt1 gene is responsible for dwg and dwg (Bayer) mutations. In this study we characterized dwg mutations by investigating their association with the Ggt1 gene. Histological analysis revealed reduced numbers of proliferative and hypertrophic chondrocytes in the growth plate of dwg/dwg mice, which are characteristic abnormalities observed in GGT1-deficient mice. To identify the causative mutations of dwg mutations, we analyzed the Ggt1 gene in dwg/dwg and dwg (Bayer)/dwg (Bayer) mice. In dwg/dwg mice, 13 nucleotides on exon 7 of the Ggt1 gene were deleted, resulting in the generation of aberrant transcripts due to disrupted pre-mRNA splicing. Furthermore, dwg (Bayer)/dwg (Bayer) mice had a 46.7-kb deletion containing complete coding sequences of Ggt1 and AI646023 genes and the first exon of the Ggt5 gene, which is closely related to the Ggt1 gene as a member of the GGT gene family. These results indicate that both dwg and dwg (Bayer) have defective mutations of the Ggt1 gene. Thus, we concluded that mutations in the Ggt1 gene are responsible for the phenotypes of dwg/dwg and dwg (Bayer)/dwg (Bayer) mice.

Ketoconazole (KT) is a broad-spectrum antifungal agent whose pharmacological activity is based on the capability to interfere with steroid biosynthesis through an interaction with fungal cytochrome P-450 enzymes and thereby avoiding the formation of fungal walls. As the inhibition of fungal cytochrome P-450 by KT is not specific, the mammalian cytochrome P-450 species, which play an important role in the biosynthesis of steroidogenesis, are also affected. The reproductive and developmental toxicity of KT have been assessed. This antimycotic agent has been reported as embryotoxic and teratogenic when administered in high doses (80 mg/kg) to pregnant rats. The mechanisms by which KT exert teratogenic effects remains to be elucidated. When considering the potential inhibitory effect of KT on mammalian steroid biosynthesis as a possible responsible for the skeletal anomalies induced by this drug, this study aimed at determining whether steroid maternal supplementation may prevent the skeletal anomalies induced by KT. To test this hypothesis, maternal supplementation with prednisone (PRED) (0.1, 0.2 or 0.4 mg/kg) and 80 mg/kg of KT were administered to pregnant Wistar rats (n = 10) during organogenesis period. On gestational day 21, the dams were euthanized and examined for standard parameters of reproductive outcome. In summary, the results showed that PRED supplementation therapy may cause reductions in the incidence of KT-induced cranial and appendicular skeletal anomalies as well as cleft palate in the rat, being these results more consistent with 0.4 mg/kg of this drug. These results suggest an important role for glucocorticoids in KT-induced teratogenesis.

We have recently generated a transgenic mouse line (termed hRen-Cre) that expresses Cre-recombinase under the control of a 12.2-kb fragment of the human renin promoter. In the present study, we have crossed hRen-Cre mice with a mouse strain in which exon 1 of the Gnas gene is flanked by loxP sites. Gnas encodes the alpha-subunit of the stimulatory G protein (Gs alpha). Our aim has been to generate a mouse model with locally restricted inactivation of Gs alpha to extend studies of the role of Gs alpha function in vivo. Mice with local Cre-mediated inactivation of Gs alpha (rCre-Gs alpha) are viable and fertile. Their most obvious phenotype consists of marked skeletal malformations of the forelimbs in which computer-tomography scans reveal shortened and fused extremity bones. Extraskeletal ossifications occur in the subcutis and in skeletal muscles associated with the affected long bones. Plasma calcium, phosphate and parathyroid hormone are normal. Skin histology has demonstrated diffuse mineralization and ossification associated with the basal cells of hair follicles. This phenotype in part resembles syndromes in humans associated with loss-of-function of Gs alpha, such as Albright hereditary osteodystrophy and progressive osseous heteroplasia. The renal phenotype of rCre-Gs alpha mice is inconspicuous. Plasma renin concentration, ambient urine osmolarity, and the glomerular filtration rate of rCre-Gs alpha mice do not differ from controls. The absence of measurable functional changes in the renin-angiotensin system indicates insufficient Cre expression in juxtaglomerular granular cells in this strain of mice. Nevertheless, the present report reaffirms the importance of Gs alpha signaling for bone development and the suppression of ectopic ossification.

This study investigated the potential adverse effects of amitraz on the initiation and maintenance of pregnancy in Sprague-Dawley rats as well as its effects on embryo-fetal development after maternal exposure during the entire pregnancy period. Amitraz was administered to pregnant rats by gavage from days 1 to 19 of gestation at dose levels of 0, 3, 10, and 30 mg/kg/day. All dams underwent a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 30 mg/kg, maternal toxicity manifested as an increase in the incidence of abnormal clinical signs and a lower body weight gain and food intake. Developmental toxicity included an increase in the fetal death rate, a decrease in the litter size, and a reduction in the fetal body weight. In addition, there was an increase in the incidence of fetal external, visceral, and skeletal abnormalities. At 10 mg/kg, maternal toxicity observed included a decrease in the body weight gain and a decrease in food intake. In addition, minimal developmental toxicity, including a decrease in the fetal body weight, an increase in the visceral and skeletal aberrations, and a delay in fetal ossification. There were no signs of either maternal toxicity or developmental toxicity at 3 mg/kg. These results show that amitraz administered during the entire pregnancy period in rats is embryotoxic and teratogenic at the maternally toxic dose (i.e., 30 mg/kg/day) and is minimally embryotoxic at a minimally maternally toxic dose (i.e., 10 mg/kg/day). Under these experimental conditions, the no-observed-adverse-effect level of amitraz for both dams and embryo-fetal development is estimated to be 3 mg/kg/day.

We present unusual imaging findings of petrified ears in a 9-year-old girl with Keutel syndrome. The patient presented for a temporal bone study for hearing loss. CT scan showed middle and inner ear abnormalities along with extensive and unsuspected calcification of the external ears and ossicular ligaments. On further investigation, the patient was found to have diffuse cartilage calcification in the larynx and tracheobronchial tree, brachytelephalangism and peripheral pulmonary stenosis suggestive of Keutel syndrome. Confirmation was obtained by mutation analysis.

The mechanical loading of striated muscle is thought to play an important role in shaping bones and joints. Here, we examine skeletogenesis in late embryogenesis (embryonic day 18.5) in Myf5-/-:MyoD-/- fetuses completely lacking striated muscle. The phenotype includes enlarged and fused cervical vertebrae and postural anomalies, some viscerocranial anomalies, long bone truncation and fusion, absent deltoid tuberosity of the humerus, scapular and clavicular hypoplasia, cleft palate, and cleft sternum. In contrast, neurocranial bone development was essentially normal. While the magnitude of individual effects varied throughout the skeletal system, the results are consistent with skeletal development depending on functional muscles. Novel abnormalities in the amyogenic fetuses relative to less severely paralyzed phenotypes extend our understanding of skeletogenic dependence on embryonic muscle contraction and static loading.

Prolonged maternal magnesium sulphate infusion therapy for tocolysis of premature labour may result in secondary fetal hypermagnesaemia, which has been associated with bony abnormalities in the newborn. We report on four infants, members of two twin pregnancies, who were exposed to prolonged fetal hypermagnesaemia. Three of the infants, all appropriate for gestational age, showed abnormal radiological findings consisting of abnormal mineralisation of long-bone metaphyses owing to fetal hypermagnesaemia. The fourth infant, who was growth retarded, had normal bones. Intrauterine growth restriction appears to be protective against magnesium sulphate-induced abnormal bone mineralisation in the newborn.

Embryo-lethal and teratogenic effects caused by the cisplatin-procaine complex cis-diaminechloro-[2-(diethylamino) ethyl 4-amino-benzoate, N(4)]-chlorideplatinum(II) monohydrochloride monohydrate (DPR) were examined in CD-1 mice after a single administration of 7, 14, 21 or 28 mg/kg, injected on day 6, 9, 13 or 16 of pregnancy. At day 18 of pregnancy fetuses were removed and carefully examined for external, visceral and skeletal malformations under a dissecting microscope. A significant reduction of maternal weight gain was observed in pregnant mice after the administration of 21 (day 13) or 28 mg/kg (days 9 and 13) DPR. The exposure to DPR during the organogenesis and early histogenesis periods of prenatal development (administration on day 9 or 13) induced a significant reduction of the mean percentage of live fetuses and a significant increase of the mean percentage of dead and resorbed fetuses. A dose-dependent reduction of fetal body weight was observed in surviving specimens exposed to DPR on embryonic day 9, 13 or 16. The analysis of surviving fetuses killed on day 18 of gestation showed that a few, but statistically significant, external malformations and visceral anomalies were observed after administration of 21 or 28 mg/kg DPR on embryonic day 13. External malformations consisted of three hepato-omphalocele and six palatoschisis (one random palatoschisis was also observed at 21 mg/kg DPR given on day 9), while visceral anomalies included only renal pelvis dilatation. Skeletal anomalies affected fetuses independently of the day of treatment and were more frequent at the highest doses of DPR. They consisted of a delay in skull ossifications, vertebral and sternal anomalies, and formation of extra ribs. A low and non-significant incidence of skeletal malformations (asymmetric sternum) was noticed in fetuses. Our data demonstrated that DPR can cause embryotoxic effects if administered during the period of organogenesis and early histogenesis. Beside embryo-lethality, DPR induced growth retardation and malformations in surviving fetuses.

DW-116, 1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-l-piperazinyl)-1, 4-dihydro-4-oxoquinolone-3-carboxylic acid hydrochloride, is a newly developed fluoroquinolone antibacterial. The potential of DW-116 to induce developmental toxicity was, investigated in Sprague-Dawley rats. DW-116 was administered by gavage to pregnant rats from days 6 to 16 of gestation at dose levels of 0, 31.3, 125, and 500 mg/kg per day. All dams were subjected to caesarean section on day 20 of gestation and their fetuses were examined for external, visceral and skeletal abnormalities. At 500 mg/kg, toxic effects including clinical signs of toxicity, suppressed body weight and decreased food intake were found in dams. An increase in the resorption rate, a decrease in the litter size, a reduction in the fetal weight, and a decrease in the placental weight were also seen. In addition, various types of external, visceral, and skeletal malformations occurred at an incidence of 17.9, 74.2 and 8.3%, respectively. Characteristic malformations included oedema, cleft palate, dilated cerebral ventricle, hypoplasia of lung and ventricular septum defect. A dramatic increase in the incidence of skeletal variations (55.6%) and retardations (94.4%) and a decrease in the number of ossification centres of sternebra, metacarpals, metatarsals and sacrocaudal vertebra were also observed. At 125 mg/kg, a reduction in the placental weight and an increase in the incidence of skeletal variations were found. There were no signs of maternal toxicity or embryotoxicity at 31.3 mg/kg. These results indicate that the fluoroquinolone antibacterial DW-116 is embryotoxic and teratogenic at minimally maternally toxic dose and is minimally embryotoxic at nonmaternally toxic dose in rats.

Objective: To evaluate skeletal abnormalities on post-mortem radiographs of fetuses with Down's syndrome., Materials and Methods: Biometrical and morphological criteria, which are used for US prenatal detection of trisomy 21, were assessed. Limb long bones, biparietal diameter (BPD)/occipito-frontal diameter (OFD) ratio, ossification of nasal bones and appearance of the middle phalanx of the fifth digit (P2) in 60 fetuses with Down's syndrome were analysed and compared with 82 normal fetuses matched for gestational age (GA) from 15 to 40 weeks' gestation (WG)., Results: We observed reduced growth velocity of limb long bones during the third trimester in both groups, but the reduction was more pronounced in the trisomic group. Brachycephaly was found as early as 15 WG in Down's syndrome and continued throughout gestation (sensitivity 0.28, specificity 1). Ossification of the nasal bones, which can be detected in normal fetuses from 14 WG, was absent in one quarter of trisomic fetuses, regardless of GA. The middle phalanx of the fifth digit was evaluated by comparison with the distal phalanx (P3) of the same digit. We found that P2 was not ossified in 11/31 trisomic fetuses before 23 WG, and was either not ossified or hypoplastic in 17/29 cases after 24 WG (sensitivity 0.56, specificity 1)., Conclusions: Three key skeletal signs were present in trisomic fetuses: brachycephaly, absence of nasal bone ossification, and hypoplasia of the middle phalanx of the fifth digit. All these signs are appropriate to prenatal US screening. When present, they fully justify determination of the fetal karyotype by amniocentesis.

Four cases of acrogeria in one large family with multiple consanguineous marriages are reported. Inheritance is autosomal recessive. Evaluation of six generations of this family also showed six individuals with congenital blindness; this pedigree suggests autosomal recessive inheritance also for this disorder. Association of the two conditions was not seen in living members. The initial presentation in the patients with acrogeria was failure of growth during the first year of life, accompanied by characteristic facial appearance and cutaneous atrophy of the face and extremities. The radiologic features of these patients were acro-osteolysis, wide sutures and fontanelles, wormian bones, mandibular hypoplasia and avascular necrosis of the femoral heads. Other features were osteolysis of the clavicles, soft tissue calcification, osteoporosis and coxa valga, which have not been described in previous reported cases.

Two patients with a unique generalised bone dysplasia demonstrating severe distinctive platyspondyly are reported. This group of crippling disorders defies metabolic and histological classification. The radiographic examination is, at present, the only practical method of documentation of these rare disorders.

We present two unrelated cases with a similar pattern of multiple congenital anomalies including limb shortening, long bone angulation, and cervical lymphocele. We believe these cases to represent additional examples of a syndrome first described by Cumming et al. (1986), and by Urioste et al. (1991) and Ming et al. (1997).

Glenoid dysplasia is an anomaly of the scapula characterized by underdevelopment of the bony glenoid and adjacent part of the scapular neck which may be seen as a primary isolated condition, in patients with multiple anomalies or ill-defined syndromes, in well-described syndromes, in mucopolysaccharidoses and related conditions, and in certain skeletal dysplasias. The general subject of glenoid dysplasia is reviewed with reference to descriptions in the literature and personal observations.

We report a hitherto unknown, lethal osteochondrodysplasia in two Japanese siblings born to consanguineous parents. The skeletal abnormalities are characterised by mesomelic brachymelia with bowed forearms, a round pelvis with shortened greater sciatic notches, an ossification defect of the pubic bones, and absence of ossification centers in the cervical vertebral bodies. The associated visceral anomalies comprised periportal fibrosis and cystic dysplasia of the intrahepatic bile ducts, pancreatic ductal ectasia, a simple renal cyst, microcephaly with multifocal laminar necrosis and ectopic gray matter, dysplastic tracheobronchial cartilage, abnormal lobulation of the lung, diaphragmatic hernia, and stenotic pulmonary valve. Thrombocytopenia was present but megakaryocytes were slightly increased in the bone marrow. The patients showed various dysmorphic features including aniridia, a long palpebral fissure, prominent nasal bridge, beaked nose, flat philtrum, low-set fleshy ears, micrognathia with submucosal cleft palate, and multiple joint contractures.

Maternal diabetes is known to be a condition associated with a high frequency of fetal malformations. However, pathogenic factors for these malformations and their possible classification into different entities are not yet well established. We present the case of an infant born to a diabetic mother and affected by several malformations. This report consolidates different hypotheses put forward in recent years.

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

A morphology based imaging review is presented of the characteristic skeletal deformities associated with acardius anceps in three acardiac twins. These fetuses demonstrated poorly developed skulls, limb reduction defects, and phocomelia of the upper limbs, as well as narrow thoracic cages with or without the complete development of ribs, clavicles, scapulae, and cervical, thoracic, or lumbar vertebrae. However, their lower limbs and pelvic girdles were almost normal. The authors conclude that skeletal development is likely to be jeopardized in the area adjacent to the heart and in the cephalic portion of the body in fetuses with acardius anceps, and suggest vascular deficiency and hypoperfusion as pathogenetic mechanisms in this type of skeletal deformity.

Rbt (Rabo torcido) is a new semidominant mouse mutant with a variety of skeletal abnormalities. Heterozygous Rbt mutants display homeotic anteroposterior patterning problems along the axial skeleton that resemble Polycomb group and trithorax gene mutations. In addition, the Rbt mutant displays strong similarities to the phenotype observed in Ts (Tail-short), indicating also a homeotically transformed phenotype in these mice. We have mapped the Rbt locus to an interval of approximately 6 cM on mouse Chromosome (Chr) 11 between microsatellite markers D11Mit128 and D11Mit103. The Ts locus was mapped within a shorter interval of approximately 3 cM between D11Mit128 and D11Mit203. This indicates that Rbt and Ts may be allelic mutations. Sox9, the human homolog of which is responsible for the skeletal malformation syndrome campomelic dysplasia, was mapped proximal to D11Mit128. It is, therefore, unlikely that Ts and Rbt are mouse models for this human skeletal disorder.

We report the case of a Japanese boy whose dysmorphic features were consistent with those of Shprintzen-Goldberg syndrome. The radiological features were characterized by late-onset craniosynostosis, arachnodactyly, undermodeling of short tubular bones, mildly undermodeled and slightly bowed long bones, twisted ribs and tall vertebral bodies with elongated neural arches. Apart from the craniosynostosis, these skeletal changes resembled those of frontometaphyseal dysplasia, a well-known craniotubular dysplasia. Shprintzen-Goldberg syndrome also shares many clinical features with frontometaphyseal dysplasia.

The case of a 20-week fetus is reported with almost completely deficient ossification of the vertebral bodies and absent ossification of several long bones. This could be a unique skeletal dysplasia or the most severe end of the atelosteogenesis spectrum.

Based on the findings in 12 patients with skeletal dysplasia diagnosed antenatally, the authors propose a tailored approach to the evaluation of foetuses with shortened long bones, depending on the time of discovery, the degree of shortening and the associated findings. During the second trimester, a very short femur [2 standard deviations (SD) - 5 mm and less] most probably corresponds to a bone dysplasia, although the differential diagnosis is mainly early intra-uterine growth retardation, and the foetal skeleton should be surveyed completely in order to find supplementary features suggestive of dwarfism. Anomalies of long bones in their shape, thickness or contour, or spinal ossification disorders or undermineralisation (best evaluated at the level of calvarial bones) are most helpful in determining the type of dysplasia. A short femur (between 2 SD and 2 SD - 4 mm) may indicate growth retardation, a chromosomal anomaly or dwarfism. Follow-up examinations are mandatory in order to differentiate between them. During the third trimester a very short femur may indicate a bone dysplasia and the work-up should be the same as in the second trimester. A short femur may correspond to dwarfism of late development, a growth-retarded foetus or constitutional shortness. Various ratios, especially that of the femur/foot, are helpful in differentiating between them. In case of previous family history, a short or very short femur usually indicates recurrence of the dwarfism. In all cases of antenatal diagnosis, confirmation of the sonographic findings should be obtained either by foetal or neonatal radiographs. The approach proposed by the authors should provide sufficient information to counsel the family not only for the ongoing pregnancy but also for subsequent ones.

Perlman syndrome is a rare autosomal recessive syndrome of macrosomia and nephromegaly associated with a significant predisposition to Wilms tumor. We report a premature infant with Perlman syndrome to demonstrate additional manifestations of this condition: large cisterna magna, intestinal malrotation, and skeletal abnormalities.

Tadpoles of Rana perezi were kept for 14 weeks in water containing two sublethal levels of the carbamate insecticide ZZ-Aphox or the organophosphate Folidol. Approximate concentrations of their active ingredients were 0.25 and 1 mg/L. Resulting malformations were studied by skeletal analysis and histological and histochemical investigation of te rear limbs of the tadpoles. The pesticides caused the animals to have malformations of the spinal column (scoliosis) and/or limbs (short and thick long bones with the epiphyses grossly twisted). Histochemical study showed differences in the composition of the connective matrix, and microscopic examination of the long bones indicated alterations in the thickness of the uncalcified bone matrix (osteoid) and the presence of abundant vascularised connective tissue in the region of the periosteum. The results confirmed changes in the composition of the connective tissue matrix as the cause of the defects observed in bone formation which are also discussed in relation to vitamin D absorption and calcium homeostasis.

Osteopathia striata with cranial sclerosis (OS-CS) is a specific bone dysplasia manifested by hypertelorism, flat nasal bridge, frontal bossing, large head, hypoplastic maxilla, palate anomalies, chronic otitis media, hearing deficits, nasal obstruction, and neurological changes of deafness, facial palsy, ophthalmoplegia, and mental retardation. We will review the clinical and radiologic findings in a new patient from birth to 20 years; this is believed to be the thirty-fifth patient reported. OS-CS is 2.5 times more common in females and occurs as an autosomal dominant condition or a sporadic dominant mutation with patients presenting for evaluation from the newborn period to the fifth decade. Skeletal abnormalities are distinctive including sclerosis of the skull base and calvarium, linear striated densities in the long bones and pelvis, and poor development of the mastoid and sinus air cells. Radionuclide bone scans with SPECT indicated in our patient increased bone turnover which was supported by biochemical findings of increased pyridinoline excretion. The major complications are due to constriction of essential foramina at the skull base. The condition is not life-threatening but can produce disability.

Urogenital syndrome (us) is a recessive mutation in mice characterized primarily by abnormalities of the axial skeleton and urogenital organs. We established linkage of us with the centromeric end of Chromosome (Chr) 2, using the Robertsonian Chr Rb(2.8)2Lub. Analysis of progeny from crosses using the Chr 2 markers Danforth's short tail (Sd) and ulnaless (Ul) positioned us near two loci that have recently been mapped by RFLPs, nonerythroid alpha-spectrin (Spna-2) and the paired-box-containing-gene-8 (Pax-8). The position of us relative to these loci was established by analysis of progeny from interspecific backcrosses between the us strains and Mus spretus. The estimated map distances and most likely gene order are centromere-Pax-8-2.1 +/- 1.2-us-0.7 +/- 0.7-Spna-2; however, the reverse order cannot be ruled out. Our data make it unlikely that us is a mutation in either Spna-2 or Pax-8. Spna-2 is close enough to us, however, to be a useful marker for positional cloning of the us gene. The human mutation Nail-patella-syndrome (NPS1) maps to the region of human Chr 9 (9q34) that is homologous to the us region of mouse Chr 2. Phenotypic similarities between the two syndromes suggest the possibility that they are caused by mutations at homologous loci.

The Schinzel-Giedion syndrome is a rare autosomal recessive condition with typical facies, skeletal manifestations and congenital hydronephrosis. We report an infant with characteristic findings who had bilateral congenital megacalyces. Congenital megacalyces is believed to be a developmental abnormality, occurs in other malformation syndromes and has not previously been described in the Schinzel-Giedion syndrome.

Two strikingly similar twin sisters presented with characteristic facial anomalies and distinctive radiographic findings. The occurrence of this unique pattern of malformations in two sisters with unaffected parents suggests recessive inheritance. They most likely represent a previously unrecognised malformation syndrome.

We describe a girl who presents the features of Wiedemann-Rautenstrauch syndrome. This autosomal recessive condition has characteristic radiographic findings which can be considered manifestations of the syndrome.

Prenatal toxicity of toluene was determined in two separate studies by inhalation exposure of Himalayan rabbits. In the first study 15 artificially inseminated females per group were exposed to 30, 100, or 300 ppm and in the second study 20 artificially inseminated females per group inhaled 100 or 500 ppm. In each case the rabbits were exposed for 6 hours per day from day 6 post-insemination (p.i.) to day 18 p.i. The respective controls inhaled conditioned clean air under the same exposure conditions. No signs of maternal toxicity were observed. All data obtained on gestational parameters were found to be within the variation range reported for this rabbit strain. The fetal external, soft tissue and skeletal findings were seen in toluene exposed fetuses in a frequency similar to the corresponding and/or historical controls. Differences observed between the groups were not concentration dependent and were considered incidental rather than compound related. Therefore, toluene was not embryotoxic, fetotoxic, or teratogenic for rabbits exposed during the period of organogenesis. The highest concentration tested under these conditions (500 ppm) was found to be a no-observable-adverse-effect level (NOAEL) for both the adult and the fetal Himalayan rabbit. Based on these and previous results of animal studies of prenatal toxicity, a safety or uncertainty factor approach is considered for setting limits of exposure for women at workplaces. A pregnancy guidance value of 20 ppm is proposed.

Occipital horn syndrome, a rare genetic disorder of copper metabolism, was recognized in 2 unrelated patients. Radiographs of these patients at various ages allowed confirmation of previously described radiographic findings. In addition, new radiographic manifestations were encountered. These pathognomonic radiographic findings are presented and the clinical and biochemical features of occipital horn syndrome are reviewed.

Cartilage-hair hypoplasia is a metaphyseal chondrodysplasia with short-limbed short stature. In childhood radiographs the metaphyseal regions of the tubular bones are widened, scalloped and irregularly sclerotic. We have analyzed radiological characteristics and skeletal growth in 149 radiographic surveys of 82 Finnish patients. All extremity long bones were affected and short for age. The growth failure was progressive. In the adults the median relative lengths were for the humerus -6.3 SD, radius -8.6 SD, ulna -6.7 SD, femur -9.7 SD, tibia -8.7 SD, and fibula -6.8 SD. the severity of the metaphyseal changes correlated with the degree of the growth failure. The skeletal age was markedly retarded in 14% of the patients. Caudal widening of the interpediculate distance in the lumbar spine was observed in 90% of the patients, but it tended to be less than normal. The sagittal diameter of the spinal canal was normal in the cervical region but decreased in the lumbar region. Mild scoliosis was observed in one-fourth of the patients, and its incidence increased with age. Lumbar lordosis was moderately increased. Thoracic deformity was observed in 82% of the patients. The relative interorbital distance was increased with the median of +2.2 SD in the adults.

Experimental teratogenic models of the campomelic syndrome in duck and chick embryos and in frog tadpoles are presented. The association of selective growth impairment of the peripheral and facial nerve trunks including the spinal cord and nerve roots is suggested as an underlying cause for adaptive shortening of the corresponding skeletal parts. Buckling may occur because the growing bones tend to accommodate to these underdeveloped neurological structures even at the cost of a deformity. It is suggested that investigation of the effects of "skeletal" teratogens upon the nervous system may be more logical than concentrating upon bone growth which may be the secondary effect.

The Authors describe two patients aged 5 and 8, a female and a male, affected by a condition of polymalformations known as Kabuki make-up or Niikawa-Kuroki syndrome, having a neonatal incidence of 1:32,000 in Japan. There are two hypothesis about the apparent rarity of the syndrome in the rest of the world, including the Asian Continent: the first is that it exists, but is infrequently recognized outside Japan and the second is that it is really more frequent in those parts of the world, where ethnic exchanges are uncommon, as it happens in Japan.

We present, a family manifesting a variation of the syndrome of ectrodactyly with tibial apasia. The principal case in the family showed the most severe bilateral skeletal malformations of this syndrome. The hand changes of this case (tetra-oligodactyly with missing 5th rays) and of a relative (oligodactyly with the last 3 rays being affected) reflected a variable manifestation of "ectrodactyly". Additionally, a review of the relevant literature is presented for further delineation of various aspects of this syndrome.

We report on an infant male who presented with microcephaly of prenatal onset, schizencephaly, decorticated disturbance of the neurological function, congenital optic atrophy, abnormal eye movements and nystagmus. In addition, he had a skeletal dysplasia with predominant acromelic involvement and a renal disease characterized by both nephritic and nephrotic changes. The natural history of his condition included severe postnatal failure to thrive, lack of development of psychomotor milestones, intractable seizures, terminal renal insufficiency with early death. Such spectrum of phenotypic abnormalities has never been reported before and we suggest that it may represent a new syndromic entity. The differential diagnosis with the oculo-skeletal-renal syndromes, with the osteodysplastic primordial dwarfism of the Taybi-Linder type and with the Hutterite cerebro-osteo-nephrodysplasia, is discussed.

Enterolithiasis in two neonates with oesophageal and anorectal atresia is reported. The features of the two cases and comparison with the literature, the particular appearance of these intracolonic calcifications and the importance of radiological examinations for associated digestive, urinary and pulmonary malformations are presented.

The response of pregnant marmosets (Callithrix jacchus) to the thalidomide derivative EM 12 was evaluated. EM 12 was selected for these studies because it is more active than thalidomide and is much more stable for hydrolysis. Skeletal gross structural abnormalities were observed when EM 12 was given to marmosets for 3-7 days during the period between days 49 and 60 post ovulation. Using the treatment schedule finally adapted in our laboratory, i.e. treatment during days 51-57 post ovulation, doses of 5 (or 10) mg EM 12/kg body wt induced the typical limb abnormalities known from man with an 80-100% certainty. In some animals we could observe the typical pattern of abnormalities even with doses as low as 1 mg EM 12/kg body wt. Abnormalities of the skeleton induced during this sensitive period are described. None of these (except some bifurcations of ribs) were seen in any of the ten litters (23 fetuses) serving as controls during the period of the study.

The clinical and radiographic features of 47 cases of neonatally manifest osteogenesis imperfecta were analyzed. A scoring system was devised to code the degree of skeletal changes. A score of 2.7 and more carried a prospective mortality of 88%. Scores of 2.6 and less were associated with a survival rate of 90%. The prognosis was particularly favourable in a subgroup of patients characterized by marked bowing of the lower extremities, mild involvement of the rest of the skeleton and white sclerae. Neonates with these features tended to have a good long-term prognosis, with few additional fractures and partial or total spontaneous resolution of the limb deformity. The study confirmed the genetic and prognostic heterogeneity of the disorder, which comprises several autosomal dominant and recessive entities.