6‐Mercaptopurine modifies cerebrospinal fluid T cell abnormalities in paediatric opsoclonus–myoclonus as steroid sparer

The purpose of this study was to evaluate the capacity of 6‐mercaptopurine (6‐MP), a known immunosuppressant, to normalize cerebrospinal fluid (CSF) lymphocyte frequencies in opsoclonus–myoclonus syndrome (OMS) and function as a steroid sparer. CSF and blood lymphocytes were immunophenotyped in 11 children with OMS (without CSF B cell expansion) using a comprehensive panel of cell surface adhesion, activation and maturation markers by flow cytometry, and referenced to 18 paediatric controls. Drug metabolites, lymphocyte counts and liver function tests were used clinically to monitoring therapeutic range and toxicity. In CSF, adjunctive oral 6‐MP was associated with a 21% increase in the low percentage of CD4⁺ T cells in OMS, restoring the CD4/CD8 ratio. The percentage of CD4⁺ T cells that were interferon (IFN)‐γ⁺ was reduced by 66%, shifting the cytokine balance away from T helper type 1 (Th1) (proinflammatory) predominance. The percentage of natural killer (NK) cells decreased significantly in CSF (–32%) and blood (–67 to ?82%). Low blood absolute lymphocyte count was more predictive of improvement in CSF lymphocyte proportions (correlated with % CD4⁺ T cells) than the 6‐thioguanine level (no correlation). 6‐MP was difficult to titrate: 50% achieved the target absolute lymphocyte count (< 1·5 K/mm); 20%, the ‘therapeutic’ 6‐thioguanine level; and 40% the non‐toxic 6‐methylmercaptopurine level. Side effects and transaminase elevation were mild and reversible. Clinical steroid‐sparing properties and lowered relapse frequency were demonstrated. 6‐MP displayed unique pharmacodynamic properties that may be useful in OMS and other autoimmune disorders. Its steroid sparer capacity is limited to children in whom the therapeutic window can be reached without limiting pharmacokinetic factors or side effects.     

Cerebrospinal fluid γδ T cell frequency is age‐related: a case–control study of 435 children with inflammatory and non‐inflammatory neurological disorders

Studies of cerebrospinal fluid (CSF) γδ T cells in children are limited, due especially to the lack of control data. In adults, gamma/delta T cells (TCR‐γδ) residing in the intrathecal space are sometimes involved in neuroinflammation. To evaluate the possible role of γδ T cells in paediatric neuroinflammation, we immunophenotyped cerebrospinal fluid (CSF) and blood lymphocytes using flow cytometry in a case–control study of 100 children with non‐inflammatory neurological disorders (NIND), 312 with opsoclonus–myoclonus (OMS) and 23 with other inflammatory neurological disorders (OIND). In NIND, the negative correlation between CSF γδ T cell frequency and patient age was striking: median frequency of 27% in infants and 3·3% in teens. Interindividual variations were largest in the youngest. There was no gender effect. In all OMS, after correcting for age, only a small effect of OMS severity remained. Measurement of markers for γδ T cell activation [human leucocyte antigen D‐related (HLA‐DR)], maturation (CD45RA, CD45RO) or intracellular cytokine staining [interleukin (IL)‐4, interferon (IFN)‐γ] failed to discriminate OMS and NIND groups. Of seven OMS immunotherapies/combinations, none altered the frequency of total CSF γδ T cells or subsets significantly. In OIND, the CSF γδ T cell frequency was < 10% for single samples of other paraneoplastic disorders [anti‐neuronal nuclear antibody (ANNA)‐1, PCA‐1, teratoma‐associated syndrome], cerebellar ataxia (post‐infectious, ataxia‐telangiectasia), acute disseminated encephalomyelitis, neuroborreliosis and encephalitis. This study provides new insights into CSF γδ T cells in the paediatric population. Although their role in CSF remains elusive, the negative age correlation, resistance to immunotherapy and our age cut‐off references for NIND are important findings for the design of future paediatric studies.     

CCR3 functional responses are regulated by both CXCR3 and its ligands CXCL9, CXCL10 and CXCL11

The chemokine receptor CXCR3 is predominantly expressed on T lymphocytes, and its agonists CXCL9, CXCL10 and CXCL11 are IFN-gamma-inducible chemokines that promote Th1 responses. In contrast, the CCR3 agonists CCL11, CCL24 and CCL26 are involved in the recruitment of cells such as eosinophils and basophils during Th2 responses. Here, we report that although CCL11, CCL24 and CCL26 are neither agonists nor antagonists of CXCR3, CCL11 binds with high affinity to CXCR3. This suggests that, in vivo, CXCR3 may act as a decoy receptor, sequestering locally produced CCL11. We also demonstrate that the CXCR3 ligands inhibit CCR3-mediated functional responses of both human eosinophils and CCR3 transfectants induced by all three eotaxins, with CXCL11 being the most efficacious antagonist. The examination of CCR3-CCR1 chimeric constructs revealed that CCL11 and CXCL11 share overlapping binding sites contained within the CCR3 extracellular loops, a region that was previously shown to be essential for effective receptor-activation. Hence, eosinophil responses mediated by chemokines acting at CCR3 may be regulated by two distinct mechanisms: the antagonistic effects of CXCR3 ligands and the sequestration of CCL11 by CXCR3-expressing cells. Such interplay may serve to finely tune inflammatory responses in vivo.     

Apparent Smith–Lemli–Opitz syndrome in a child with a previously undescribed form of mucolipidosis not involving the neurons

A diagnosis of Smith–Lemli–Opitz syndrome was made shortly after birth in a small-fordates infant, on the basis of a characteristic face, penoscrotal hypospadias, bilateral postaxial hexadactyly, and bilateral syndactyly of toes 2–3. The clinical course was marked by failure to thrive, severe delay, refractory myoclonic jerks beginning at age 2 months, and increasing hepatosplenomegaly. He developed corneal clouding and increased gingival hypertrophy and died at age 18 weeks. Autopsy disclosed widespread storage of mucopolysaccharides and lipids within the macrophages and, to a lesser extent, parenchymal cells, of all organ systems. There was extensive demyelination of the cerebral white matter, and dystrophic calcification in the cerebrum, cerebellum, and brainstem. There was no evidence of primary neuronal involvement in the storage. Although the chance concurrence of 2 uncommon diseases is rare, a causal link between the clinical anomalies and the storage disorder cannot be argued convincingly on the basis of one case. Careful pathologic studies of other children who die with clinical signs compatible with Smith–Lemli–Opitz syndrome are indicated.     

Differential expression of CXCR3 targeting chemokines CXCL10, CXCL9, and CXCL11 in different types of skin inflammation

Recruitment of activated T-cells to the skin is a common feature in a wide variety of inflammatory skin diseases. As CXCR3 activating chemokines CXCL10 (IP-10), CXCL9 (Mig), and CXCL11 (IP-9/I-TAC) specifically attract activated T-cells, this study addressed the question of whether differences in the expression of these chemokines correlate with the site and cellular composition of the skin infiltrates in different types of inflammatory skin disease. Skin biopsies from lichen planus, chronic discoid lupus erythematosus, allergic patch test reactions, psoriasis, and Jessner's lymphocytic infiltration of the skin were investigated for chemokine expression using RNA in situ hybridization, and for the expression of CXCR3 using immunohistochemistry. The results showed differential expression of CXCL10, CXCL9, and CXCL11, which correlated with differences in the localization and cellular composition of the infiltrates. Whereas CXCL10 and CXCL11 were mainly expressed by basal keratinoctyes, CXCL9 mRNA expression was located predominantly in the dermal infiltrates. Correlation with immunohistochemical data suggested that macrophages and activated keratinocytes were the main producers of these chemokines. CXCR3 was expressed by a majority of both CD4+ and CD8+ infiltrating T-cells, suggesting a functional interaction between locally produced chemokines and CXCR3-expressing T-cells. In conclusion, these findings indicate that these CXCR3 activating chemokines play a significant role in the recruitment and maintenance of T-cell infiltrates in the inflammatory skin diseases studied.     

A 69‐year‐old woman with Coffin–Siris syndrome

Coffin–Siris syndrome (CSS) is a rare intellectual disability syndrome classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and other digits, distinctive facial features, hirsutism/hypertrichosis, and sparce scalp hair. It is genetically heterogeneous but most often caused by a pathogenic variant in the ARID1B gene. Previous clinical reports of CSS patients are mainly based on young or middle‐aged individuals. Here, we report a 69‐year‐old woman with CSS phenotype and a pathogenic ARID1B loss‐of‐function variant c.5259_5260dup. She has severe intellectual disability but otherwise she is in relatively good health both physically and mentally. There is no evident history of chronic illness or progressive disability. CSS appears to be compatible with long survival and most likely it is underdiagnosed in geriatric patients with intellectual disability.     

Myoclonus‐dystonia and Silver–Russell syndrome resulting from maternal uniparental disomy of chromosome 7

Myoclonus‐dystonia (M‐D) is a movement disorder that is often associated with mutations in epsilon‐sarcoglycan (SGCE), a maternally imprinted gene at 7q21.3. We report a 24‐year‐old male with short stature (<5th percentile) and a movement disorder clinically consistent with M‐D. Single nucleotide polymorphism (SNP) array did not identify significant copy number changes, but revealed three long continuous stretches of homozygosity on chromosome 7 suggestive of uniparental disomy. Parental SNP arrays confirmed that the proband had maternal uniparental disomy of chromosome 7 (mUPD7) with regions of heterodisomy and isodisomy. mUPD7 is the cause of approximately 5–10% of Silver–Russell syndrome (SRS), a disorder characterized by prenatal and postnatal growth retardation. Although SRS was not suspected in our patient, these findings explain his short stature. SGCE methylation testing showed loss of the unmethylated paternal allele. Our findings provide a unifying diagnosis for his short stature and M‐D and help to optimize his medication regimen. In conclusion, we show that M‐D is a clinical feature that may be associated with SRS due to mUPD7. Individuals with mUPD7 should be monitored for the development of movement disorders. Conversely, individuals with M‐D and short stature should be evaluated for SRS.     

Common variants of chemokine receptor gene CXCR3 and its ligands CXCL10 and CXCL11 associated with vascular permeability of dengue infection in peninsular Malaysia

Dengue causes significantly more human disease than any other arboviruses. It causes a spectrum of illness, ranging from mild self-limited fever, to severe and fatal dengue hemorrhagic fever, as evidenced by vascular leakage and multifactorial hemostatic abnormalities. There is no specific treatment available till date. Evidence shows that chemokines CXCL10, CXCL11 and their receptor CXCR3 are involved in severity of dengue, but their genetic association with the susceptibility of vascular leakage during dengue infection has not been reported. We genotyped 14 common variants of these candidate genes in 176 patients infected with dengue. rs4859584 and rs8878 (CXCL10) were significantly associated with vascular permeability of dengue infection (P < 0.05); while variants of CXCL11 showed moderate significance of association (P = 0.0527). Haplotype blocks were constructed for genes CXCL10 and CXCL11 (5 and 7 common variants respectively). Haplotype association tests performed revealed that, “CCCCA” of gene CXCL10 and “AGTTTAC” of CXCL11 were found to be significantly associated with vascular leakage (P = 0.0154 and 0.0366 respectively). In summary, our association study further strengthens the evidence of the involvement of CXCL10 and CXCL11 in the pathogenesis of dengue infection.     

Genetic,epidemiologic and clinicopathologic studies of Japanese Asian patients with Birt–Hogg–Dubé syndrome

Birt–Hogg–Dubé syndrome (BHD) is a rare genetic disorder characterized by fibrofolliculomas, pulmonary cysts and renal cell carcinomas (RCCs). The affected individuals inherit germline mutations in the folliculin gene (FLCN). We investigated the mutation spectrum and clinicopathologic findings of 312 patients from 120 different families (119 Japanese and 1 Taiwanese). A total of 31 different FLCN sequence variants were identified. The majority were c.1285dupC (n = 34), c.1533_1536delGATG (n = 25), and c.1347_1353dupCCACCCT (n = 19). Almost all patients presented with pulmonary cysts. The incidence of RCCs in FLCN mutation carriers over the age of 40 was 34.8% (40/115). Fifty‐five RCC lesions were surgically resected; most were either chromophobe RCC (n = 24; 43.6%) or hybrid oncocytic/chromophobe tumors (19; 34.5%). Seventy‐six of 156 FLCN mutation carriers (120 probands and 36 sibs, 48.7%) had skin papules; however, cutaneous manifestations were so subtle that only one patient voluntarily consulted dermatologists. Japanese Asian BHD families have three FLCN mutational hotspots. Recurrent episodes of pneumothoraces are the major symptoms suggestive of a BHD diagnosis in our cohort. Characteristic features of lung and kidney lesions may be more informative than fibrofolliculomas as diagnostic criteria for BHD in the Japanese Asian population.     

Elsahy–Waters syndrome is caused by biallelic mutations in CDH11

Elsahy–Waters syndrome (EWS), also known as branchial–skeletal–genital syndrome, is a distinct dysmorphology syndrome characterized by facial asymmetry, broad forehead, marked hypertelorism with proptosis, short and broad nose, midface hypoplasia, intellectual disability, and hypospadias. We have recently published a homozygous potential loss of function variant in CDH11 in a boy with a striking resemblance to EWS. More recently, another homozygous truncating variant in CDH11 was reported in two siblings with suspected EWS. Here, we describe in detail the clinical phenotype of the original CDH11‐related patient with EWS as well as a previously unreported EWS‐affected girl who was also found to have a novel homozygous truncating variant in CDH11, which confirms that EWS is caused by biallelic CDH11 loss of function mutations. Clinical features in the four CDH11 mutation‐positive individuals confirm the established core phenotype of EWS. Additionally, we identify upper eyelid coloboma as a new, though infrequent clinical feature. The pathomechanism underlying EWS remains unclear, although the limited phenotypic data on the Cdh11^?/? mouse suggest that this is a potentially helpful model to explore the craniofacial and brain development in EWS‐affected individuals.

     

Mutations in WNT9B are associated with Mayer–Rokitansky–Küster–Hauser syndrome

Mayer–Rokitansky–Küster–Hauser syndrome (MRKHS) is a well‐known malformation pattern of the Müllerian ducts (MDs) characterized by congenital absence of the uterus and vagina. To date, most cases remain unexplained at molecular level. As female Wnt9b‐/‐ mice show a MRKHS‐like phenotype, WNT9B has emerged as a promising candidate gene for this disease. We performed retrospective sequence analyses of WNT9B in 226 female patients with disorders of the MDs, including 109 patients with MRKHS, as well as in 135 controls. One nonsense mutation and five likely pathogenic missense mutations were detected in WNT9B. Five of these mutations were found in cases with MRKHS accounting for 4.6% of the patients with this phenotype. No pathogenic mutations were detected in the control group (p = 0.017). Interestingly, all of the MRKHS patients with a WNT9B mutation were classified as MRKHS type 1, representing 8.5% of the cases from this subgroup. In previous studies, two of the patients with a WNT9B mutation were found to carry either an additional deletion of LHX1 or a missense mutation in TBX6. We conclude that mutations in WNT9B were frequently associated with MRKHS in our cohort and some cases may be explained by a digenic disease model.     

Phelan–McDermid syndrome: Clinical report of a 70‐year‐old woman

Phelan–McDermid or 22q13.3 deletion syndrome is characterized by global intellectual disability, childhood hypotonia, severely delayed or absent speech, features of autism spectrum disorder, without any major dysmorphisms or somatic anomalies. It is typically diagnosed before adolescence and data about adult patients are virtually absent. The expression of its phenotypical characteristics appears to be linearly related to the deletion size. Here, an intellectually disabled geriatric female patient is described with a long history of challenging behaviors in whom Phelan–McDermid syndrome was demonstrated. Detailed analysis of the patient's history and functioning resulted in a psychiatric diagnosis of atypical bipolar disorder and her behavior significantly improved upon maintenance treatment with a mood stabilizing agent. The present article confirms recent findings that atypical bipolar disorder may be part of the psychopathological phenotype of Phelan–McDermid syndrome, reason why careful etiological search is warranted, also in the geriatric population. © 2012 Wiley Periodicals, Inc.