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Camurati–Engelmann disease is characterized by hyperostosis of the long bones and the skull, muscle atrophy, severe limb pain, and progressive joint contractures in some patients. It is caused by heterozygous mutations in the transforming growth factor β1 (TGFβ1) believed to result in improper folding of the latency-associated peptide domain of TGFβ1 and thus in increased or deregulated bioactivity. Losartan, an angiotensin II type 1 receptor antagonist, has been found to downregulate the expression of TGFβ type 1 and 2 receptors. Clinical trials with losartan have shown a benefit in Marfan syndrome, while trials are underway for Duchenne muscular dystrophy and other myopathies associated with TGFβ1 signaling. We hypothesized that due to its anti-TGFβ1 activity, losartan might be beneficial in Camurati–Engelmann disease. This report concerns a boy who presented at age 13 years with severe limb pain and difficulty in walking. Clinical and radiographic evaluation results were compatible with Camurati–Engelmann disease and the diagnosis was confirmed by mutation analysis (c.652C > T [p.Arg218Cys]). The boy underwent an experimental treatment with losartan at a dosage of 50 mg/day, orally. During the treatment period of 18 months, the intensity and frequency of limb pain decreased significantly (as shown by a pain diary), and muscle strength improved, allowing the boy to resume walking and climbing stairs. No obvious side effects were observed. We cautiously conclude that TGFβ1 inhibition with losartan deserves further evaluation in the clinical management of Camurati–Engelmann disease. © 2014 Wiley Periodicals, Inc.

Item does not contain fulltext We used exome sequencing of blood DNA in four unrelated patients to identify the genetic basis of metaphyseal chondromatosis with urinary excretion of D-2-hydroxy-glutaric acid (MC-HGA), a rare entity comprising severe chondrodysplasia, organic aciduria, and variable cerebral involvement. No evidence for recessive mutations was found; instead, two patients showed mutations in IDH1 predicting p.R132H and p.R132S as apparent somatic mosaicism. Sanger sequencing confirmed the presence of the mutation in blood DNA in one patient, and in blood and saliva (but not in fibroblast) DNA in the other patient. Mutations at codon 132 of IDH1 change the enzymatic specificity of the cytoplasmic isocitrate dehydrogenase enzyme. They result in increased D-2-hydroxy-glutarate production, alpha-ketoglutarate depletion, activation of HIF-1alpha (a key regulator of chondrocyte proliferation at the growth plate), and reduction of N-acetyl-aspartyl-glutamate level in glial cells. Thus, somatic mutations in IDH1 may explain all features of MC-HGA, including sporadic occurrence, metaphyseal disorganization, and chondromatosis, urinary excretion of D-2-hydroxy-glutaric acid, and reduced cerebral myelinization.

The cardinal features of Primrose syndrome (MIM 259050) are dysmorphic facial features, macrocephaly, and intellectual disability, as well as large body size, height and weight, and calcified pinnae. A variety of neurological signs and symptoms have been reported including hearing loss, autism, behavioral abormalities, hypotonia, cerebral calcifications, and hypoplasia of the corpus callosum. Recently, heterozygous de novo missense mutations in ZBTB20, coding for a zing finger protein, have been identified in Primrose syndrome patients. We report a boy with intellectual disability carrying two de novo missense mutations in the last exon of ZBTB20 (Ser616Phe and Gly741Arg; both previously unreported). One of them, Ser616Phe, affects an amino acid located in one of the C2H2 zing-fingers involved in DNA-binding and close to other missense mutations already described. Reverse phenotyping showed that this patient presents with classic features of Primrose syndrome (dysmorphic facies, macrocephaly, hearing loss, hypotonia, hypoplasia of the corpus callosum) and, in addition, congenital hypothyroidism. Review of the literature reveals another Primrose syndrome patient with hypothyroidism and thus, this may represent an under recognized component that should be investigated in other patients. © 2016 Wiley Periodicals, Inc.

Cerebral, ocular, dental, auricular, skeletal anomalies (CODAS) syndrome (MIM 600373) was first described and named by Shehib et al, in 1991 in a single patient. The anomalies referred to in the acronym are as follows: cerebral-developmental delay, ocular-cataracts, dental-aberrant cusp morphology and delayed eruption, auricular-malformations of the external ear, and skeletal-spondyloepiphyseal dysplasia. This distinctive constellation of anatomical findings should allow easy recognition but despite this only four apparently sporadic patients have been reported in the last 20 years indicating that the full phenotype is indeed very rare with perhaps milder or a typical presentations that are allelic but without sufficient phenotypic resemblance to permit clinical diagnosis. We performed exome sequencing in three patients (an isolated case and a brother and sister sib pair) with classical features of CODAS. Sanger sequencing was used to confirm results as well as for mutation discovery in a further four unrelated patients ascertained via their skeletal features. Compound heterozygous or homozygous mutations in LONP1 were found in all (8 separate mutations; 6 missense, 1 nonsense, 1 small in-frame deletion) thus establishing the genetic basis of CODAS and the pattern of inheritance (autosomal recessive). LONP1 encodes an enzyme of bacterial ancestry that participates in protein turnover within the mitochondrial matrix. The mutations cluster at the ATP-binding and proteolytic domains of the enzyme. Biallelic inheritance and clustering of mutations confirm dysfunction of LONP1 activity as the molecular basis of CODAS but the pathogenesis remains to be explored.

We report on a consanguineous Arab family in which three sibs had an unusual skeletal dysplasia characterized by anterior defects of the spine leading to severe lumbar kyphosis and marked brachydactyly with cone epiphyses. The clinical phenotype also included dysmorphic facial features, epilepsy, and developmental delay. This constellation likely represents a previously undescribed skeletal dysplasia, most probably inherited in an autosomal recessive pattern. A homozygosity mapping approach has thus far failed to unearth the responsible gene as the region shared by these three sibs is 27.7 Mb in size and contains over 200 genes with no obvious candidate. © 2014 Wiley Periodicals, Inc.

We report on a series of 514 consecutive diagnoses of skeletal dysplasia made over an 8-year period at a tertiary hospital in Kerala, India. The most common diagnostic groups were dysostosis multiplex group (n = 73) followed by FGFR3 (n = 49) and osteogenesis imperfecta and decreased bone density group (n = 41). Molecular confirmation was obtained in 109 cases. Clinical and radiographic evaluation was obtained in close diagnostic collaboration with expert groups abroad through Internet communication for difficult cases. This has allowed for targeted biochemical and molecular studies leading to the correct identification of rare or novel conditions, which has not only helped affected families by allowing for improved genetic counseling and prenatal diagnosis but also resulted in several scientific contributions. We conclude that (1) the spectrum of genetic bone disease in Kerala, India, is similar to that of other parts of the world, but recessive entities may be more frequent because of widespread consanguinity; (2) prenatal detection of skeletal dysplasias remains relatively rare because of limited access to expert prenatal ultrasound facilities; (3) because of the low accessibility to molecular tests, precise clinical-radiographic phenotyping remains the mainstay of diagnosis and counseling and of gatekeeping to efficient laboratory testing; (4) good phenotyping allows, a significant contribution to the recognition and characterization of novel entities. We suggest that the tight collaboration between a local reference center with dedicated personnel and expert diagnostic networks may be a proficient model to bring current diagnostics to developing countries. © 2014 Wiley Periodicals, Inc.

Long-term observations of individuals with the so-called Langer-Giedion (LGS) or tricho-rhino-phalangeal type II (TRPS2) are scarce. We report here a on follow-up of four LGS individuals, including one first described by Andres Giedion in 1969, and review the sparse publications on adults with this syndrome which comprises ectodermal dysplasia, multiple cone-shaped epiphyses prior to puberty, multiple cartilaginous exostoses, and mostly mild intellectual impairment. LGS is caused by deletion of the chromosomal segment 8q24.11-q24.13 containing among others the genes EXT1 and TRPS1. Most patients with TRPS2 are only borderline or mildly cognitively delayed, and few are of normal intelligence. Their practical skills are better than their intellectual capability, and, for this reason and because of their low self-esteem, they are often underestimated. Some patients develop seizures at variable age. Osteomas on processes of cervical vertebrae may cause pressure on cervical nerves or dissection of cerebral arteries. Joint stiffness is observed during childhood and changes later to joint laxity causing instability and proneness to trauma. Perthes disease is not rare. Almost all males become bald at or soon after puberty, and some develop (pseudo) gynecomastia. Growth hormone deficiency was found in a few patients, TSH deficiency so far only in one. Puberty and fertility are diminished, and no instance of transmission of the deletion from a non-mosaic parent to a child has been observed so far. Several affected females had vaginal atresia with consequent hydrometrocolpos.

Focal dermal hypoplasia (FDH; Goltz-Gorlin syndrome; OMIM 305600) is a disorder that features involvement of the skin, skeletal system, and eyes. It is caused by loss-of-function mutations in the PORCN gene. We report a young girl with FDH, microphthalmos associated with colobomatous orbital cyst, dural ectasia and cystic malformation of the spinal cord, and a de novo variant in PORCN. This association has not been previously reported, and based on these observations the phenotypic spectrum of FDH might be broader than previously appreciated. It would be prudent to alter the suggested surveillance for this rare disorder.

The Simpson–Golabi–Behmel syndrome type 1 (SGBS1, OMIM #312870) is an X-linked overgrowth condition comprising abnormal facial appearance, supernumerary nipples, congenital heart defects, polydactyly, fingernail hypoplasia, increased risk of neonatal death and of neoplasia. It is caused by mutation/deletion of the GPC3 gene. We describe a macrosomic 27-week preterm newborn with SGBS1 who presents a novel GPC3 mutation and emphasize the phenotypic aspects which allow a correct diagnosis neonatally in particular the rib malformations, hypoplasia of index finger and of the same fingernail, and 2nd–3rd finger syndactyly. © 2012 Wiley Periodicals, Inc.

Dominant mutations in the receptor calcium channel gene TRPV4 have been associated with a family of skeletal dysplasias (metatropic dysplasia, pseudo-Morquio type 2, spondylometaphyseal dysplasia, Kozlowski type, brachyolmia, and familial digital arthropathy) as well as with dominantly inherited neuropathies (hereditary motor and sensory neuropathy 2C, scapuloperoneal spinal muscular atrophy, and congenital distal spinal muscular atrophy). While there is phenotypic overlap between the various members of each group, the two groups were considered to be totally separate with the former being strictly a structural skeletal condition and the latter group being confined to the peripheral nervous system. We report here on fetal akinesia as the presenting feature of severe metatropic dysplasia, suggesting that certain TRPV4 mutations can cause both a skeletal and a neuropathic phenotype. Three cases were detected on prenatal ultrasound because of absent movements in the second trimester. Case 4 presented with multiple joint contractures and absent limb movements at birth and was diagnosed with "fetal akinesia syndrome". Post-interruption and post-natal X-rays showed typical features of metatropic dysplasia in all four. Sequencing of the TRPV4 gene confirmed the presence of de novo heterozygous mutations predicting G78W (Case 1), T740I (Cases 2 and 3), and K276E (Case 4). Although some degree of restriction of movements is not uncommon in fetuses with skeletal dysplasia, akinesia as leading sign is unusual and suggests that certain TRPV4 mutations produce both chondrodysplasia and a peripheral neuropathy resulting in a severe "overlap" phenotype.

Axial spondylometaphyseal dysplasia (SMD) (OMIM 602271) is an uncommon skeletal dysplasia characterized by metaphyseal changes of truncal-juxtatruncal bones, including the proximal femora, and retinal abnormalities. The disorder has not attracted much attention since initially reported; however, it has been included in the nosology of genetic skeletal disorders [Warman et al. (2011); Am J Med Genet Part A 155A:943-968] in part because of a recent publication of two additional cases [Isidor et al. (2010); Am J Med Genet Part A 152A:1550-1554]. We report here on the clinical and radiological manifestations in seven affected individuals from five families (three sporadic cases and two familial cases). Based on our observations and Isidor's report, the clinical and radiological hallmarks of axial SMD can be defined: The main clinical findings are postnatal growth failure, rhizomelic short stature in early childhood evolving into short trunk in late childhood, and thoracic hypoplasia that may cause mild to moderate respiratory problems in the neonatal period and later susceptibility to airway infection. Impaired visual acuity comes to medical attention in early life and function rapidly deteriorates. Retinal changes are diagnosed as retinitis pigmentosa or pigmentary retinal degeneration on fundoscopic examination and cone-rod dystrophy on electroretinogram. The radiological hallmarks include short ribs with flared, cupped anterior ends, mild spondylar dysplasia, lacy iliac crests, and metaphyseal irregularities essentially confined to the proximal femora. Equally affected sibling pairs of opposite gender and parental consanguinity are strongly suggestive of autosomal recessive inheritance.

We recently reported on the deficiency of carbohydrate sulfotransferase 3 (CHST3; chondroitin-6-sulfotransferase) in six subjects diagnosed with recessive Larsen syndrome or humero-spinal dysostosis [Hermanns et al. (2008); Am J Hum Genet 82:1368–1374]. Since then, we have identified 17 additional families with CHST3 mutations and we report here on a series of 24 patients in 23 families. The diagnostic hypothesis prior to molecular analysis had been: Larsen syndrome (15 families), humero-spinal dysostosis (four cases), chondrodysplasia with multiple dislocations (CDMD “Megarbane type”; two cases), Desbuquois syndrome (one case), and spondylo-epiphyseal dysplasia (one case). In spite of the different diagnostic labels, the clinical features in these patients were similar and included dislocation of the knees and/or hips at birth, clubfoot, elbow joint dysplasia with subluxation and limited extension, short stature, and progressive kyphosis developing in late childhood. The most useful radiographic clues were the changes of the lumbar vertebrae. Twenty-four different CHST3 mutations were identified; 16 patients had homozygous mutations. We conclude that CHST3 deficiency presents at birth with congenital dislocations of knees, hips, and elbows, and is often diagnosed initially as Larsen syndrome, humero-spinal dysostosis, or chondrodysplasia with dislocations. The incidence of CHST3 deficiency seems to be higher than assumed so far. The clinical and radiographic pattern (joint dislocations, vertebral changes, normal carpal age, lack of facial flattening, and recessive inheritance) is characteristic and distinguishes CHST3 deficiency from other disorders with congenital dislocations such as filamin B-associated dominant Larsen syndrome and Desbuquois syndrome. © 2010 Wiley-Liss, Inc.

Recent discoveries have established the existence of a family of skeletal dysplasias caused by dominant mutations in TRPV4. This family comprises, in order of increasing severity, dominant brachyolmia, spondylo-metaphyseal dysplasia Kozlowski type, and metatropic dysplasia. We tested the hypothesis that a further condition, Spondylo-epiphyseal dysplasia (SED), Maroteaux type (MIM 184095; also known as pseudo-Morquio syndrome type 2), could be caused by TRPV4 mutations. We analyzed six individuals with Maroteaux type SED, including three who had previously been reported. All six patients were found to have heterozygous TRPV4 mutations; three patients had unreported mutations, while three patients had mutations previously described in association with metatropic dysplasia. In addition, we tested one individual with a distinct rare disorder, parastremmatic dysplasia (MIM 168400). This patient had a common, recurrent mutation seen in several patients with Kozlowski type spondylo-metaphyseal dysplasia. We conclude that SED Maroteaux type and parastremmatic dysplasia are part of the TRPV4 dysplasia family and that TRPV4 mutations show considerable variability in phenotypic expression resulting in distinct clinical-radiographic phenotypes.

Raine syndrome is an autosomal recessive condition with generalized osteosclerosis, characteristic facial dysmorphism and brain abnormalities including intracerebral calcifications. We report on a case with Raine syndrome born to nonconsanguineous couple and report the prenatal sonogram/MRI, the fetopathology, and neuropathology findings.

Skeletal dysplasias induced by mutations in the collagen 2 gene (the so-called "type 2 collagenopathies") form a wide spectrum in severity and are distinguished by subtle clinical and radiographic differential signs. The unifying features are predominant involvement of the vertebral bodies and the epiphyses of the long bones ("spondylo-epiphyseal" pattern). A mild degree of metaphyseal dysplasia can be seen in the so-called Strudwick variant of spondyloepimetaphyseal dysplasia and is generally mild or absent in other forms. We report here on four individuals with COL2A1 mutations associated with marked metaphyseal involvement with only mild epiphyseal and spondylar changes. One patient who carried a Gly283Arg substitution had a pattern of metaphyseal dysplasia that corresponded precisely to what was termed "Murdoch type metaphyseal dysplasia" in 1960s and was renamed Strudwick type SEMD in 1980s; the second patient carried a Gly181Arg substitution and had severe metaphyseal dysplasia with fractures at the metaphyses reminiscent of the "corner fractures" or Sutcliffe type spondylometaphyseal dysplasia. The third patient also had major metaphyseal involvement but more epiphyseal changes than the others in this study and had a Gly922Arg mutation in COL2A1. The final patient had a small in-frame deletion and unusually ballooned and distorted metaphyses. While it remains true that most individuals with COL2A1 mutations have chondrodysplasia with a spondylo-epiphyseal pattern, metaphyseal involvement is not incompatible with a COL2A1 dysplasia and mutation analysis can be indicated. The observation of these individuals with metaphyseal dysplasia indicates that the phenotypic spectrum associated with mutations in type 2 collagen, the main cartilage protein, is even wider than hitherto assumed.

Platyspondylic lethal skeletal dysplasia (PLSD) Torrance type (PLSD-T) is a rare skeletal dysplasia characterized by platyspondyly, brachydactyly, and metaphyseal changes. Generally a perinatally lethal disease, a few long-term survivors have been reported. Recently, mutations in the carboxy-propeptide of type II collagen have been identified in two patients with PLSD-T, indicating that PLSD-T is a type 2 collagen-associated disorder. We studied eight additional cases of PLSD-T and found that all had mutations in the C-propeptide domain of COL2A1. The mutational spectrum includes missense, stop codon and frameshift mutations. All non-sense mutations were located in the last exon, where they would escape non-sense-mediated RNA-decay. We conclude that PLSD-T is caused by mutations in the C-propeptide domain of COL2A1, which lead to biosynthesis of an altered collagen chain (as opposed to a null allele). Similar mutations have recently been found to be the cause of spondyloperipheral dysplasia, a non-lethal dominant disorder whose clinical and radiographical features overlap those of the rare long-term survivors with PLSD-T. Thus, spondyloperipheral dysplasia and PLSD-T constitute a novel subfamily within the type II collagenopathies, associated with specific mutations in the C-propeptide domain and characterized by distinctive radiological features including metaphyseal changes and brachydactyly that set them apart from other type 2 collagenopathies associated with mutations in the triple-helical domain of COL2A1. The specific phenotype of C-propeptide mutations could result from a combination of diminished collagen fibril formation, toxic effects through the accumulation of unfolded collagen chains inside the chondrocytes, and alteration of a putative signaling function of the carboxy-propeptide of type 2 collagen. © 2005 Wiley-Liss, Inc.

Bruck syndrome (BS) is a recessively-inherited phenotypic disorder featuring the unusual combination of skeletal changes resembling osteogenesis imperfecta (OI) with congenital contractures of the large joints. Clinical heterogeneity is apparent in cases reported thus far. While the genes coding for collagen 1 chains are unaffected in BS, there is biochemical evidence for a defect in the hydroxylation of lysine residues in collagen 1 telopeptides. One BS locus has been mapped at 17p12, but more recently, two mutations in the lysyl hydroxylase 2 gene (PLOD2, 3q23-q24) have been identified in BS, showing genetic heterogeneity. The proportion of BS cases linked to 17p22 (BS type 1) or caused by mutations in PLOD2 (BS type 2) is still uncertain, and phenotypic correlations are lacking. We report on a boy who had congenital contractures with pterygia at birth and severe OI-like osteopenia and multiple fractures. His urine contained high amounts of hydroxyproline but low amounts of collagen crosslinks degradation products; and he was shown to be homozygous for a novel mutation leading to an Arg598His substitution in PLOD2. The mutation is adjacent to the two mutations previously reported (Gly601Val and Thr608Ile), suggesting a functionally important hotspot in PLOD2. The combination of pterygia with bone fragility, as illustrated by this case, is difficult to explain; it suggests that telopeptide lysyl hydroxylation must be involved in prenatal joint formation and morphogenesis. Collagen degradation products in urine and mutation analysis of PLOD2 may be used to diagnose BS and differentiate it from OI.

The term "spondyloperipheral dysplasia" (SPD) has been applied to the unusual combination of platyspondyly and brachydactyly as observed in a small number of individuals. The reported cases show wide clinical variability and the nosologic status and spectrum of this condition are still ill defined. Zabel et al. [1996: Am J Med Genet 63(1):123-128] reported an individual with short stature and SPD who was heterozygous for a frameshift mutation in the C-propeptide domain of COL2A1. To explain the additional finding of brachydactyly that is not an usual feature of the type II collagenopathies, it was postulated that the nature of the mutation induced precocious calcification and premature fusion of metacarpal and phalangeal growth plates. The C-propeptide of collagen II had previously been found to promote calcification ("chondrocalcin"). We have ascertained two further individuals with clinical and radiological findings of a type II collagenopathy in infancy who developed brachydactyly type E like changes of fingers and toes in childhood. In both individuals, heterozygosity for novel, distinct mutations in the C-propeptide coding region of COL2A1 were found. Although all three mutations (the one previously reported and the two novel ones) predict premature termination, their location close to the 3'-end of the mRNA probably protects them from nonsense-mediated decay and allows for synthesis of mutant procollagen chains. However, loss of crucial cysteine residues or other sequences essential for trimerization prevents these chains from associating and participating in procollagen helix formation, and thus leads to accumulation in the ER-consistent with EM findings. The mechanism leading to precocious fusion of phalangeal epiphyses remains to be explored. The consistency of clinical, radiographic, and molecular findings in these three unrelated individuals confirms SPD as a distinct nosologic entity. The diagnosis of SPD is suggested by the appearance of brachydactyly in a child who has clinical and radiographic features of a collagen II disorder.

Mutations in the diastrophic dysplasia sulfate transporter (DTDST) gene result in a family of skeletal dysplasias, which comprise lethal (achondrogenesis type 1B and atelosteogenesis type 2) and non-lethal conditions (diastrophic dysplasia and recessive multiple epiphyseal dysplasia (rMED)). The most frequent mutation is R279W, which in a homozygous state results in rMED with bilateral clubfoot, MED, and "double layered" patella. We describe three patients with rMED caused by a previously unreported homozygous mutation in the DTDST gene. The three patients (from two families) were born to healthy, non-consanguineous parents. All developed signs of hip dysplasia in early childhood and two had episodes of recurrent patella dislocation. Two underwent bilateral total hip replacements at ages 13 and 14 years. The feet, external ears, and palate were normal. Stature was normal in all cases. Radiographs showed dysplastic femoral heads, mild generalized epiphyseal dysplasia, abnormal patella ossification, and normal hands and feet. Direct sequence analysis of genomic DNA demonstrated a homozygous 1984TA (C653S) change in the DTDST gene in all patients. The clinically normal parents were heterozygous for the change. This is the first description of a homozygous C653S mutation of the DTDST gene. Hip dysplasia and patella hypermobility dominates the otherwise mild phenotype. These patients further expand the range of causative mutations in the DTD skeletal dysplasia family.

Boomerang dysplasia, atelosteogenesis type 1 and Piepkorn dysplasia are bone dysplasias with an overlapping clinical spectrum characterized by deficient formation and ossification of specific elements of the skeleton. Typical symptoms include micromelia with diminished ossification, and a characteristic bowed and boomerang-like aspect of the long tubular bones. We report here a new case of boomerang dysplasia, which was detected prenatally in the 16th week of gestation by ultrasound.