Localised Wegener's Granulomatosis Presenting as an Orbital Pseudotumour with Extension into the Posterior Cranial Fossa

Pseudotumour has rarely been reported to invade the intracranial cavity. We present a case of pseudotumour which extended intra-cranially into the posterior cranial fossa. The patient had circulating antineutrophil cytoplasmic antibodies in titres diagnostic for Wegener's granulomatosis. In the absence of clinical renal or respiratory tract disease, the case may represent a newly recognized sub-type of “localised” Wegener's granulomatosis.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Mutation analysis of the STRA6 gene in isolated and non-isolated anophthalmia/microphthalmia

PDAC syndrome [Pulmonary hypoplasia/agenesis, Diaphragmatic hernia/eventration, Anophthalmia/microphthalmia (A/M) and Cardiac Defect] is a condition associated with recessive mutations in the STRA6 gene in some of these patients. Recently, cases with isolated anophthalmia have been associated with STRA6 mutations. To determine the minimal findings associated with STRA6 mutations, we performed mutation analysis of the STRA6 gene in 28 cases with anophthalmia. In 7 of the cases the anophthalmia was isolated, in 14 cases it was associated with one of the major features included in PDAC and 7 had other abnormalities. Mutations were identified in two individuals: one with bilateral anophthalmia and some features included in PDAC, who was a compound heterozygote for a missense mutation and a large intragenic deletion, and the second case with all the major features of PDAC and who had a homozygous splicing mutation. This study suggests that STRA6 mutations are more likely to be identified in individuals with A/M and other abnormalities included in the PDAC spectrum, rather than in isolated A/M cases.

Infrequent mutation of the p53 gene in fibrous tumors of infancy and childhood

Mutations in the p53 tumor suppressor gene occur in > 50% of human malignancies, but are exceedingly rare in benign tumors. The malignant potential of fibrous tumors of children may be unpredictable at microscopic examination. We therefore sought to determine whether malignant fibrous tumors could be distinguished from their benign counterparts by the presence of mutations in p53. We screened 27 fibrous tumor samples from 20 young patients. Tumors were classified as benign, borderline, or malignant by conventional microscopic criteria. RNA extracted from each specimen was used as the template for reverse transcription followed by polymerase chain reaction (PCR) amplification, with six pairs of primers covering the whole coding region of the p53 gene. All PCR products were screened for the presence of mutations using single-strand conformation polymorphism analysis. In addition, PCR products encompassing exons 5-9, the sites of the most frequent mutations in human tumors, were sequenced directly. Both methods detected a single point mutation in a highly malignant tumor (malignant fibrous histiocytoma). The mutation was a silent one at codon 36 (CCG-CCA, Pro-Pro). We conclude that p53 mutations are infrequent in childhood fibrous tumors, consistent with previous observations of low malignant potential (< 10%) and better prognosis in this tumor group. Therefore, screening for p53 mutations is not a useful prognostic indicator in fibrous tumors with borderline pattern at microscopic examination.

Chronic dermal sinuses as a manifestation of histiocytosis X

Two young patients presented with generalised lymphadenopathy, otorrhoea, otitis, and rash. Over the next few years chronically discharging sinuses began to form over enlarged nodes and histological appearances were typical of histiocytosis X. In neither case were micro-organisms isolated from the lesions, and in both patients healing occurred with immunosuppressive agents. Chronic dermal sinus formation secondary to lymph node disease has never before been recorded as a manifestation of histiocytosis X. Histiocytosis X should therefore be considered in the differential diagnosis of "suppurative" lymphadenopathy so that appropriate treatment may be given without delay.

Human syncytiotrophoblast membrane proteins defined using a heterologous antiserum

Detergent extracts of human trophoblast plasma membranes (TrPM) and of other fetal tissues from the same conceptus were prepared and the proteins separated by use of isoelectric focusing. A major band of isoelectric point (pI) 4.1 was present in TrPM together with minor bands of (pI) 4.9, 5.9, 7.3, 7.8 and 7.9. These bands were absent from non-trophoblastic fetal tissues. The pI 4.1 protein reacted with an 125I-labelled IgG fraction of a heterologous antiserum raised against TrPM and was found to have an apparent molecular weight of 100,000. This protein did not appear to be placental alkaline phosphatase, SP1, transferrin or human chorionic gonadotrophin. Many neoplastic cell lines tested also revealed a major protein band of pI 4.1 but it has not been established that this was the same protein as found in the TrPM preparations.