More than 97% of achondroplasia cases are caused by one of two mutations (G1138A and G1138C) in the fibroblast growth factor receptor 3 (FGFR3) gene, which results in a specific amino acid substitution, G380R. Sporadic cases of achondroplasia have been associated with advanced paternal age, suggesting that these mutations occur preferentially during spermatogenesis. We have determined the parental origin of the achondroplasia mutation in 40 sporadic cases. Three distinct 1-bp polymorphisms were identified in the FGFR3 gene, within close proximity to the achondroplasia mutation site. Ninety-nine families, each with a sporadic case of achondroplasia in a child, were analyzed in this study. In this population, the achondroplasia mutation occurred on the paternal chromosome in all 40 cases in which parental origin was unambiguous. This observation is consistent with the clinical observation of advanced paternal age resulting in new cases of achondroplasia and suggests that factors influencing DNA replication or repair during spermatogenesis, but not during oogenesis, may predispose to the occurrence of the G1138 FGFR3 mutations.

ABSTRACT

The P253R mutation appears to be associated with the more severe forms, with regard to the forms of syndactyly and to mental outcome. The fact that mutations found in patients with Apert' s syndrome are usually confined to a specific region of the FGFR2 exon IIIa may be useful in making the diagnosis and allowing genetic counseling in difficult cases.

Amoebic encephalitis is an uncommon and usually fatal condition. This case describes successful treatment of a Balamuthia mandrillaris brain abscess using prolonged antimicrobial agents with complete excision. It illustrates the risk of dissemination from cutaneous to cerebral amoebic lesions, potential progression with corticosteroid therapy, and the prospect for curative excision.

The spectrum of nitrofurantoin lung injury continues to widen. The case histories are presented of two patients who developed lung disease associated with the use of nitrofurantoin with histological features of bronchiolitis obliterans organising pneumonia (BOOP), a rare but recognised form of drug induced injury. The two middle aged women presented with respiratory symptoms after prolonged treatment with nitrofurantoin. Both had impaired lung function and abnormal computed tomographic scans, and their condition improved when nitrofurantoin was withdrawn and corticosteroid treatment commenced. The favourable outcome in these two patients contrasts with the fatal outcome of the two other reported cases of nitrofurantoin induced BOOP. We suggest that the previous classification of nitrofurantoin induced lung injury into "acute" and "chronic" injury is an oversimplification in view of the wide variety of pathological entities that have subsequently emerged.

Object Apert's syndrome is characterized by faciocraniosynostosis and severe bony and cutaneous syndactyly of all four limbs. The molecular basis for this syndrome appears remarkably specific: two adjacent amino acid substitutions (either S252W or P253R) occurring in the linking region between the second and third immunoglobulin domains of the fibroblast growth factor receptor (FGFR)2 gene. The goal of this study was to examine the phenotype/genotype correlations in patients with Apert's syndrome. Methods In the present study, 36 patients with Apert's syndrome were screened for genetic mutations. Mutations were detected in all cases. In one of the patients there was a rare mutation consisting of a double-base pair substitution in the same codon (S252F). A phenotypical survey of our cases was performed and showed the clinical variability of this syndrome. The P253R mutation appears to be associated with the more severe forms of Apert's syndrome with regard to the forms of syndactyly and to mental outcome. In two patients there was no clinical or radiological evidence of craniosynostosis. In two other patients with atypical forms of syndactyly and cranial abnormalities, the detection of a specific mutation was helpful in making the diagnosis. Conclusions The fact that mutations found in patients with Apert's syndrome are usually confined to a specific region of the FGFR2 exon IIIa may be useful in making a diagnosis.

We previously generated a conditional floxed mouse line to study androgen action, in which exon 3 of the androgen receptor (AR) gene is flanked by loxP sites, with the neomycin resistance gene present in intron 3. Deletion of exon 3 in global AR knockout mice causes androgen insensitivity syndrome, characterized by genotypic males lacking normal masculinization. We now report that male mice carrying the floxed allele (AR(lox)) have the reverse phenotype, termed hyperandrogenization. AR(lox) mice have increased mass of androgen-dependent tissues, including kidney, (P < 0.001), seminal vesicle (P < 0.001), levator ani muscle (P = 0.001), and heart (P < 0.05). Serum testosterone is not significantly different. Testis mass is normal, histology shows normal spermatogenesis, and AR(lox) males are fertile. AR(lox) males also have normal AR mRNA levels in kidney, brain, levator ani, liver, and testis. This study reaffirms the need to investigate the potential phenotypic effects of floxed alleles in the absence of cre in tissue-specific knockout studies. In addition, this androgen hypersensitivity model may be useful to further investigate the effects of subtle perturbations of androgen action in a range of androgen-responsive systems in the male.

Background: Spiradenocarcinoma is a rare skin adnexal neoplasm that may behave aggressively. It is often associated with a benign slow-growing spiradenoma that has undergone malignant transformation. Given the paucity of cases in the literature, there is a lack of consensus on treatment. Methods: The terms 'malignant spiradenoma' or 'spiradenocarcinoma' were systematically used to search the PubMed, MEDLINE and Google Scholar databases. A total of 182 cases of spiradenocarcinoma were identified as eligible for this comprehensive literature review. Results: Spiradenocarcinoma was commoner in older age and Caucasian race. In most cases, surgical excision for local disease is the mainstay of treatment. Lymph node dissection is usually reserved for those with suspected or confirmed lymph node metastases. High rates of local recurrence (20.8%), metastasis (37.4%) and mortality (19.1%) were identified, prompting some authors to suggest regular follow up including chest X-rays and liver function tests. Conclusions: Patients with spiradenocarcinoma may benefit from a magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography/computed tomography to establish the extent of disease. We recommend wide local excision as the treatment of choice to achieve surgical margins of ≥1 cm, with node resection to be determined on a case-to-case basis. Regular follow up is important given the high rate of local recurrence, metastasis and mortality. This should include an examination of the regional lymph nodes. Further research is required to refine an evidence-based approach to spiradenocarcinoma.