Abstract C038: Repeat RNA dysregulation of cellular states in the pancreatic cancer microenvironment

Aberrant transcription of the repeat RNAs is a common feature in epithelial cancers including PDAC, but the function of these non-coding RNAs in cancer development is relatively unexplored. We have found that these repeat RNAs are sensed and replicate like retroviruses, and now have identified the ability of these viral-like elements to be transmitted from cancer cells through extracellular vesicles (EVs). PDAC-derived EVs applied to cancer-associated fibroblasts (CAFs) activates interferon-stimulated genes (ISGs) and is able to drive CAFs towards an inflammatory CAF (iCAF) phenotype with concordant loss of myofibroblast CAF (myCAF) marker genes. Using in-vitro transcription, we demonstrate that individual repeat RNAs (HSATII, HERVK (env), LINE-1 5’UTR and LINE-1 3’UTR) are sufficient to induce ISG response in CAFs with HSATII and HERVK (env) having the most potent ISG response. In contrast, PDAC cells were found to induce epithelial-mesenchymal transition (EMT) with loss of epithelial gene expression. To determine the potential sensor of HSATII repeat RNAs, we utilized CRISPR/Cas9 knockout of the viral RNA sensors RIG-I, MDA5, and MAVS in PDAC and CAF cells. Notably, these sensors were important for PDAC repeat RNA sensing and response, but not in CAF cells. Evaluating the innate immune pathway further downstream, we used genetic knockout of IRF3 with CRISPR/Cas9 knockout and find significant downregulation of key EMT genes that are shared with myCAF markers (ACTA2, FN1, SERPINE1). Interestingly, HSATII RNA activated IRF3 dependent EMT genes in PDAC cells, but induced IRF3 degradation in CAF cells that results in loss of myCAF gene expression. Furthermore, we found that conditioned media from HSATII transfected CAF activates EMT-related gene expression (ACTA2, FN1, SERPINE1) in PDAC cell lines, which indicates an cell extrinsic mechanism to augment EMT induction in PDAC cells. We utilized next generation spatial transcriptomic platforms NanoString GeoMx and CosMx to understand the spatial distribution of repeat RNAs in human PDAC tumors. We find that repeat RNAs can be found as a gradient from PDAC cells to the surround tumor microenvironment consistent with delivery of these RNA species. Analysis of over 300,000 individual cells in 3 PDAC tumor specimens, we find that high repeat PDAC cells have lost epithelial gene expression and high repeat CAFs have lost myCAF gene expression. Altogether, these findings support the “infection” of repeat RNAs disrupts cellular identity in both tumor cells and the CAF microenvironment as a mechanism for tumor progression.

Citation Format: Eunae You, Luli Zou, Patrick Danaher, Ildiko E. Phillips, Michael J. Raabe, Bidish Patel, Amaya Pankaj, Khrystyna North, Sean Kim, Youngmi Kim, Martin Aryee, David T. Ting. Repeat RNA dysregulation of cellular states in the pancreatic cancer microenvironment [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C038.

Modulation of BCL-2 in both T Cells and Tumor Cells to Enhance Chimeric Antigen Receptor T cell Immunotherapy against Cancer

Chimeric Antigen Receptor T-cell (CART) immunotherapy led to unprecedented responses in patients with refractory/relapsed B-cell non-Hodgkin lymphoma (NHL); nevertheless, two-thirds of patients fail this treatment. Resistance to apoptosis is a key feature of cancer cells that associates with treatment failure. In 87 NHL patients treated with anti-CD19 CART, we found that chromosomal alteration of BCL-2, a critical anti-apoptotic regulator, in lymphoma cells was associated with reduced survival. Therefore, we combined CART19 with the FDA-approved BCL-2-inhibitor, venetoclax, and demonstrated in vivo synergy in venetoclax-sensitive NHL. However, higher venetoclax doses for venetoclax-resistant lymphomas resulted in CART toxicity. To overcome this limitation, we developed venetoclax-resistant CART by overexpressing mutated BCL-2(F104L) which is not recognized by venetoclax. Notably, BCL-2(F104L)-CART19 synergized with venetoclax in multiple lymphoma xenograft models. Furthermore, we uncovered that BCL-2 overexpression in T cells per se enhanced CART anti-tumor activity in preclinical models and in patients by prolonging CART persistence.

Synthetic introns enable splicing factor mutation-dependent targeting of cancer cells

Many cancers carry recurrent, change-of-function mutations affecting RNA splicing factors. Here, we describe a method to harness this abnormal splicing activity to drive splicing factor mutation-dependent gene expression to selectively eliminate tumor cells. We engineered synthetic introns that were efficiently spliced in cancer cells bearing SF3B1 mutations, but unspliced in otherwise isogenic wild-type cells, to yield mutation-dependent protein production. A massively parallel screen of 8,878 introns delineated ideal intronic size and mapped elements underlying mutation-dependent splicing. Synthetic introns enabled mutation-dependent expression of herpes simplex virus-thymidine kinase (HSV-TK) and subsequent ganciclovir (GCV)-mediated killing of SF3B1-mutant leukemia, breast cancer, uveal melanoma and pancreatic cancer cells in vitro, while leaving wild-type cells unaffected. Delivery of synthetic intron-containing HSV-TK constructs to leukemia, breast cancer and uveal melanoma cells and GCV treatment in vivo significantly suppressed the growth of these otherwise lethal xenografts and improved mouse host survival. Synthetic introns provide a means to exploit tumor-specific changes in RNA splicing for cancer gene therapy.

Coordinated missplicing of TMEM14C and ABCB7 causes ring sideroblast formation in SF3B1-mutant myelodysplastic syndrome

SF3B1 splicing factor mutations are near-universally found in myelodysplastic syndromes (MDS) with ring sideroblasts (RS), a clonal hematopoietic disorder characterized by abnormal erythroid cells with iron-loaded mitochondria. Despite this remarkably strong genotype-to-phenotype correlation, the mechanism by which mutant SF3B1 dysregulates iron metabolism to cause RS remains unclear due to an absence of physiological models of RS formation. Here, we report an induced pluripotent stem cell model of SF3B1-mutant MDS that for the first time recapitulates robust RS formation during in vitro erythroid differentiation. Mutant SF3B1 induces missplicing of ∼100 genes throughout erythroid differentiation, including proposed RS driver genes TMEM14C, PPOX, and ABCB7. All 3 missplicing events reduce protein expression, notably occurring via 5' UTR alteration, and reduced translation efficiency for TMEM14C. Functional rescue of TMEM14C and ABCB7, but not the non-rate-limiting enzyme PPOX, markedly decreased RS, and their combined rescue nearly abolished RS formation. Our study demonstrates that coordinated missplicing of mitochondrial transporters TMEM14C and ABCB7 by mutant SF3B1 sequesters iron in mitochondria, causing RS formation.

583 Exploring the potential of T cell acute lymphoblastic leukemia (T-ALL) for generating leukemia-specific T cell responses that can be therapeutically harnessed with immunotherapy

Background

T cell Acute Lymphoblastic Leukemia (T-ALL) is a devastating malignancy found primarily in pediatric populations. Unfortunately, standard of care for T-ALL has not progressed from highly toxic, intensive regimens of chemotherapy, which fails to cure all patients. Immunotherapies designed to activate patients‘ leukemia-specific T cells may provide a new therapeutic avenue to increase complete response rates, reduce toxicity without the need to engineer (e.g. CAR) cells. However, it is unknown whether T-ALL is capable of being recognized by T cells due given its relatively low mutation-rate. These studies therefore sought to investigate whether signs of leukemia-specific T cell responses are generated by T-ALL. Because T-ALL results in systemic disease and infiltrates multiple lymphoid and non-lymphoid tissues, these studies also determined how the divergent immune contextures of these TMEs impacts T cell responses to T-ALL. From this, we aim to identify immunotherapeutic targets capable of activating T cells across tissues to eradicate leukemia systemically.

Methods

Primary leukemia cells isolated from a spontaneous murine model (LN3 mice) into immune-competent, congenic (CD45.1) recipient mice. Tissues were harvested at distinct stages of disease for analysis by flow cytometry or utilizing NanoString Technologies’ GeoMX Digital Spatial Profiling (DSP) platform.

Results

Flow cytometric analysis of T cells revealed extensive changes in response to T-ALL that included multiple features of exhaustion typically associated with anti-tumor responses as determined by upregulation of co-inhibitory receptors and TOX. This included a surprisingly high-frequency of PD1+ T cells, which was accompanied by PDL1- and PDL2-expressing myeloid cells that likely are restraining these subsets. Importantly, combination immunotherapy with OX40 agonists while inhibiting PD1 resulted in drastically reduced tumor burden and concomitant expansion of proliferating granzyme-expressing CD8 T cells. To gain better insight into T cell responses within distinct organs, we analyzed tissue sections using DSP. This technique enabled us to evaluate T cells in direct contact with leukemia infiltrates compared to T cells in regions without T-ALL, which further revealed an enrichment of activated subsets. Importantly, these studies have provided critical insight needed to better understand how T cells responding to T-ALL diverge between distinct types of tissues.

Conclusions

The results from these studies collectively suggest that T cells are activated by T-ALL and that they can be therapeutically harnessed despite relatively low mutation-rates. Future studies will continue analysis of individual organs and use these results to rationally design combinations of immunotherapies by tailoring to activate T cells in all tissue types.

Acknowledgements

Special thanks to all the support and analysis from everyone at NanoString, along with financial support provided by a SITC-NanoString DSP Fellowship awarded to Dr. Todd Triplett used for DSP analysis of all frozen tissues in these studies. Salary support for Dr. Triplett and pilot funding was provided by departmental funds via a Cancer Prevention and Research Institute of Texas (CPRIT) Scholar Award (Grant #RR160093; awarded to Dr. Gail Eckhardt).

934 Biological mechanisms in the different etiologies of Merkel cell carcinoma patients: polyomavirus or UV exposure

Background

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer with neuroendocrine features, and it is associated with elevated mortality. The pathogenesis is associated with presence of clonally integrated Merkel cell polyomavirus (MCPyV) or ultraviolet light (UV) exposure.1 The MCPyV causes up to 80% of MCC tumors in North America and Europe.2–4 Recently immunotherapy is having good results,5 the phase 2 trial JAVELIN Merkel 200 indicated that treatment with Avelumab (PDL1 inhibitor) in patients with metastatic MCC pre-treated have a meaningful long-term survival outcomes respect chemotherapy. Moreover, ORRs were highest in patients with high TMB that were also MCPyV−, PD-L1+ or had a greater CD8+ T cell density at the invasive margin.6 In this study, we investigated the biological signatures in patients with MCPyV or not.

Methods

From April 2011 to June 2018, we collected retrospectively 50 FFPE (Formalin-Fixed Paraffin-Embed) from 37 patients with metastatic MCC and 13 tissues from a secondary metastatic site. All patients have appropriately signed informed consent. We performed an immunohistochemistry assays (IHC) for MCPyV and PDL1. In addition, through the NanoString GeoMx DSP (Digital Spatial Profiling), we analysed 11 patients (6 MCPyV+; 5 MCPyV-) with cutaneous metastasis using a 44-plex antibody cocktail. For each slide we selected three different areas: Intratumoral, extratumoral and tumour border, in each area we selected CD4+ and CD8+ cells in 4 different ROIs (Region of Interest). Statistical analysis was performed via Bonferroni correction, P< 0.05 was considered statistically significant for median stratification.

Results

The DSP analysis showed that the tumour border cells have an overexpression of IDO respect intratumoral area (adj. p<0.01). Instead, extratumoral area of MCPyV- patients have a higher expression of B7-H3 respect MCPyV+ as well as FOXP3 is higher in the tumour border of MCPyV+ patients and EpCAM in the intratumoral area (p<0.05). PDL1 is overexpressed in MCPyV+ CD4+ cells respect CD8+ (p<0.05). The IHC assay shown that viral status does not change in multiple metastases and PDL1 is elevated in the tumour border (p<0.05).

Conclusions

In this retrospective study, our preliminary data shown that tumour edge have an important role in the modulations of immune infiltrate and patients with Merkel cell polyomavirus could have a different pathway of immunosuppression compared to patients with non-virus related etiology. Further investigations are needed to get additional information.

Acknowledgements

The study was supported by the Institutional Project ”Ricerca Corrente” of Istituto Nazionale Tumori IRCCS Fondazione ”G. Pascale” of Napoli, Italy.

References

Kaae J, Hansen AV, Biggar RJ, et al. Merkel cell carcinoma: incidence, mortality, and risk of other cancers. J Natl Cancer Inst 2010 June 2;102(11):793–801.

Feng H, Shuda M, Chang Y, et al. Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008 February 22;319(5866):1096–100.

Garneski KM, Warcola AH, Feng Q, et al. Merkel cell polyomavirus is more frequently present in North American than Australian Merkel cell carcinoma tumors. J Invest Dermatol 2009 January;129(1):246–8.

Goh G, Walradt T, Markarov V, et al. Mutational landscape of MCPyV-positive and MCPyV-negative Merkel cell carcinomas with implications for immunotherapy. Oncotarget 2016 January 19;7(3):3403–15.

Bichakjian CK, Olencki T, Aasi SZ, et al. Merkel cell carcinoma, version 1.2018, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw 2018 June;16(6):742–774.

D’Angelo SP, Bhatia S, Brohl AS, et al. Avelumab in patients with previously treated metastatic Merkel cell carcinoma: long-term data and biomarker analyses from the single-arm phase 2 JAVELIN Merkel 200 trial. J Immunother Cancer 2020 May;8(1):e000674.

Ethics Approval

The study was approved by internal ethics board of the Istituto Nazionale Tumori IRCCS Fondazione ”G. Pascale” of Napoli Italy, approval number of registry 33/17 OSS.

Consent

Written informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.

Development and Preliminary Evaluation of a Quality-of-Life Questionnaire for Adults with Neurofibromatosis Type 1 (NF1-AdQOL)

BACKGROUND

Neurofibromatosis type 1 (NF1) is a variable and unpredictable multisystem genetic disorder which predisposes to medical complications, cognitive impairment and disfigurement, of all which can impact negatively upon the health related quality of life (HRQOL) of affected adults.

OBJECTIVES

To develop and validate a disease specific HRQOL adult questionnaire to evaluate effects of NF1 from the patient's viewpoint.

METHODS

The NF1 adult HRQOL questionnaire (NF1-AdQOL) was developed based on patient interviews (n=8), survey of clinicians and piloting of the questionnaire. Adults with NF1 (n=114, 18-40 years) were recruited from three Australian genetics clinics and completed the NF1-AdQOL, Skindex-29 and Short Form-36v2 (SF-36v2) questionnaires. An exploratory factor analysis of the NF1-AdQOL was conducted to assess construct validity. Convergent and discriminant validity of the NF1-AdQOL was determined by using the multi-trait multi-method with Skindex-29 and SF-36v2 scores.

RESULTS

Factor analysis indicated that 62.7% of the common variance could be explained by three factors labelled as 'emotions associated with cosmetic appearance' (12 items), 'social functioning and learning' (11 items) and 'physical symptoms' (8 items). NF1-AdQOL had good internal consistency (Cronbach's α = 0.96). Convergent validity was confirmed by moderate associations with similarly named scales of the Skindex-29 and SF-36v2. Results from all HRQOL questionnaires indicated overall healthy HRQOL for young adults with NF1.

CONCLUSIONS

NF1-AdQOL is a relatively valid, feasible and fairly easy to read tool to measure QOL in adults with NF1. Further evaluation is required to determine its test-retest reliability, responsiveness and validity in larger adult NF1 cohorts.

Single-cell genomics reveals the genetic and molecular bases for escape from mutational epistasis in myeloid neoplasms

Large-scale sequencing studies of hematologic malignancies have revealed notable epistasis among high-frequency mutations. One of the most striking examples of epistasis occurs for mutations in RNA splicing factors. These lesions are among the most common alterations in myeloid neoplasms and generally occur in a mutually exclusive manner, a finding attributed to their synthetic lethal interactions and/or convergent effects. Curiously, however, patients with multiple-concomitant splicing factor mutations have been observed, challenging our understanding of one of the most common examples of epistasis in hematologic malignancies. In this study, we performed bulk and single-cell analyses of patients with myeloid malignancy who were harboring ≥2 splicing factor mutations, to understand the frequency and basis for the coexistence of these mutations. Although mutations in splicing factors were strongly mutually exclusive across 4231 patients (q < .001), 0.85% harbored 2 concomitant bona fide splicing factor mutations, ∼50% of which were present in the same individual cells. However, the distribution of mutations in patients with double mutations deviated from that in those with single mutations, with selection against the most common alleles, SF3B1K700E and SRSF2P95H/L/R, and selection for less common alleles, such as SF3B1 non-K700E mutations, rare amino acid substitutions at SRSF2P95, and combined U2AF1S34/Q157 mutations. SF3B1 and SRSF2 alleles enriched in those with double-mutations had reduced effects on RNA splicing and/or binding compared with the most common alleles. Moreover, dual U2AF1 mutations occurred in cis with preservation of the wild-type allele. These data highlight allele-specific differences as critical in regulating the molecular effects of splicing factor mutations as well as their cooccurrences/exclusivities with one another.

Rare and private spliceosomal gene mutations drive partial, complete, and dual phenocopies of hotspot alterations

Genes encoding the RNA splicing factors SF3B1, SRSF2, and U2AF1 are subject to frequent missense mutations in clonal hematopoiesis and diverse neoplastic diseases. Most "spliceosomal" mutations affect specific hotspot residues, resulting in splicing changes that promote disease pathophysiology. However, a subset of patients carries spliceosomal mutations that affect non-hotspot residues, whose potential functional contributions to disease are unstudied. Here, we undertook a systematic characterization of diverse rare and private spliceosomal mutations to infer their likely disease relevance. We used isogenic cell lines and primary patient materials to discover that 11 of 14 studied rare and private mutations in SRSF2 and U2AF1 induced distinct splicing alterations, including partially or completely phenocopying the alterations in exon and splice site recognition induced by hotspot mutations or driving "dual" phenocopies that mimicked 2 co-occurring hotspot mutations. Our data suggest that many rare and private spliceosomal mutations contribute to disease pathogenesis and illustrate the utility of molecular assays to inform precision medicine by inferring the potential disease relevance of newly discovered mutations.

Synthetic Lethal and Convergent Biological Effects of Cancer-Associated Spliceosomal Gene Mutations

Mutations affecting RNA splicing factors are the most common genetic alterations in myelodysplastic syndrome (MDS) patients and occur in a mutually exclusive manner. The basis for the mutual exclusivity of these mutations and how they contribute to MDS is not well understood. Here we report that although different spliceosome gene mutations impart distinct effects on splicing, they are negatively selected for when co-expressed due to aberrant splicing and downregulation of regulators of hematopoietic stem cell survival and quiescence. In addition to this synthetic lethal interaction, mutations in the splicing factors SF3B1 and SRSF2 share convergent effects on aberrant splicing of mRNAs that promote nuclear factor κB signaling. These data identify shared consequences of splicing-factor mutations and the basis for their mutual exclusivity.

Monitoring of optic nerve function in Neurofibromatosis 2 children with optic nerve sheath meningiomas using multifocal visual evoked potentials

Monitoring optic nerve sheath meningiomas (ONSM) in Neurofibromatosis type 2 (NF2) patients remains difficult. Other ocular manifestations of NF2 may obscure ophthalmic assessment of optic nerve function in these patients. Serial magnetic resonance imaging (MRI) used to assess the optic nerve is not without limitations, being expensive and often requiring general anaesthetic in children, with associated risks. This study was undertaken to describe the use of multifocal visual evoked potentials (multifocal VEP, mfVEP) in the regular monitoring of NF2 patients with ONSM. This study involved three NF2 patients with ONSM who undertook mfVEP testing at an academic ophthalmic centre. Same day mfVEP and routine ophthalmic testing were undertaken. Topographical function of the optic nerve was assessed, utilising tools such as asymmetry deviation and accumap severity index. Results were assessed alongside MRI and visual acuity (VA). From the three patients, five eyes had ONSMs, of which two caused unilateral blindness. The remaining three affected eyes had initial VAs 6/6, 6/24, and 6/18. Over follow up, ranging from 5 to 12 years, all tumours progressed, and VA declined for all patients. Multifocal VEP detected optic nerve functional loss corresponding with visual decline. This case series suggests mfVEP is effective in the objective topographic monitoring of optic nerve function in NF2 patients with ONSM. Due also to its safety in a paediatric population, the test may be considered in the routine monitoring of these patients, to be used to assist regular ophthalmic review and MRI scans.

Self-reported knee pain and disability among healthy individuals: reference data and factors associated with the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child

OBJECTIVE

To develop normative reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS-Child, as well as investigate socio-demographic, psychological and physical factors associated with knee pain and disability among healthy adults.

METHOD

The KOOS or KOOS-Child (each containing five subscales) was administered to participants aged 8-101 years within the 1000 Norms Project, an observational study of 1000 self-reported healthy individuals. Self-efficacy, physical activity, body mass index (BMI), lower limb alignment, knee frontal plane projection angle (FPPA), knee range of motion (ROM), knee and hip strength, six-minute walk, 30-second chair stand and timed up and down stairs tests were collected. KOOS data were dichotomised using established cut-off scores and logistic regression analyses were conducted for each subscale.

RESULTS

Socio-demographic characteristics were similar to the Australian population. Normative reference data were generated for children (8-17 years) and adults (18-101 years). Female adults were up to twice as likely to report knee pain, symptoms and sport/recreation (Sport/Rec) limitations compared to males (P < .05). Older age, lower self-efficacy, greater BMI, varus lower limb alignment, lower knee flexion ROM and lower hip external rotation (ER) strength were independently associated with knee pain and disability among adults.

CONCLUSIONS

Age- and gender-stratified reference data for the KOOS and KOOS-Child have been developed to guide interpretation of results in practice and research for individuals with knee disorders. Psychological and physical factors are linked with self-reported knee pain/disability among adults, and longitudinal studies to investigate causation are required.

Nemaline myopathy with exclusively intranuclear rods and a novel mutation in ACTA1 (Q139H)

Nemaline myopathies (NM) are a rare group of muscle disorders, but represent one of the most common forms of congenital myopathy. The clinical picture ranges from severe muscular hypotonia often leading to death during childhood to mild forms with long life expectancy. Diagnosis is made by muscle biopsy showing characteristic sarcoplasmic and sometimes intranuclear rod bodies. So far, disease-associated mutations have been detected in six genes without any simple correlation between genotype and phenotype or histological findings. We report a patient with a phenotype typical of congenital onset nemaline myopathy and exclusively intranuclear rods. Mutation analysis revealed a new heterozygous missense mutation in exon 3 of the ACTA1 gene (Q139H). Molecular modelling predicts that substitution of Q139 for H139 alters the amino acid side chains and hydrogen bonding which may alter the nucleotide binding cleft by adding 'bulk' to the mutated molecule. Two-dimensional gel electrophoresis demonstrates that mutant actin Q139H is expressed at approximately half the level of wild-type actin in the patient's muscle. We speculate that these alterations, although not directly affecting the nuclear export signal, negatively interfere with the nuclear export of the mutated protein and thereby cause retention of mutant actin and intranuclear rod formation.

The self-concept of children and adolescents with neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is a genetic disorder associated with cognitive deficits, learning problems, medical complications and cosmetic disfigurement. Despite the wide-ranging impact of NF1, very few studies have examined the psychosocial adjustment of individuals with NF1, and in particular, self-concept. The aims of this study were threefold: (i) to examine the self-concept of children and adolescents with NF1; (ii) to compare the self-concept of children with NF1 (NF1 only), children with NF1 and learning difficulties [NF1 + LA (low achievement)], and children with NF1 and attention deficit hyperactivity disorder (ADHD) (NF1 + ADHD); and (iii) to examine the academic self-concept of these three groups relative to objective criteria - academic achievement and teacher ratings of academic competence.

METHODS

Measures of self-concept, academic achievement and intelligence were administered to 49 children and 26 adolescents with NF1. Parents and teachers completed behavioural rating scales.

RESULTS

The majority of children and adolescents with NF1 reported positive global self-concept, with some exceptions on specific domains. Children and adolescents with NF1 reported significantly poorer self-concept for physical abilities. Adolescents also reported significantly poorer self-concept for mathematics and general self when compared with normative mean values. Clinical severity of NF1 was not a significant predictor of self-concept for physical appearance or physical abilities. Despite a significant difference between NF1 only, NF1 + LA and NF1 + ADHD groups on measures of academic achievement and teacher ratings of academic competence, there was no significant difference between the groups for academic domains of self-concept, or any other domain of self-concept. All three groups reported inflated academic self-perceptions relative to objective criteria.

CONCLUSION

Children and adolescents with NF1 are most likely to develop negative self-concepts about their physical and sporting abilities. Inflated academic self-perceptions are discussed in light of the positive illusory bias, which may serve as an adaptive or protective function.

Evaluation of primary haemostasis in people with neurofibromatosis type 1

Assessment of haemostasis in people with neurofibromatosis type 1 (NF-1) is essentially lacking, despite case reports of an association with von Willebrand disorder (VWD) and reported excessive bleeding post-surgery. We assessed routine blood haematology, routine coagulation parameters [prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen], coagulation factors II, V, VII, VIII, IX, X, XI and XII, von Willebrand (VWF) factor antigen and activity, and platelet function [using the platelet function analyser (PFA-100)] in a group of individuals with NF-1 (n = 30). Their perceived haemorrhagic bleeding risk was also graded by means of a structured clinical assessment and physical examination. Routine blood assessments including platelet counts were generally normal, as were the routine coagulation tests PT, TT and fibrinogen, and most coagulation factors. Elevated APTTs were detected in 11 individuals, reduced factor XII levels in three, reduced VWF levels in four, and elevated PFA closure times (CTs) in 13. Laboratory results correlated with each other in some but not all cases. For example, elevated APTTs were identified in two of three individuals with a reduced factor XII level and prolonged CTs were identified in three individuals who also showed reduced aggregation responses in classical platelet function studies. Moreover, all individuals with VWF results below the normal reference range showed elevated CTs with both PFA test cartridges, and those with VWF results identified as borderline normal (i.e. 50-65%) also showed elevated CTs with both PFA test cartridges in three of five cases. The relationship between VWF and CTs was also identified by linear regression analysis (P-values of <0.05, for all comparisons). However, as clinically perceived bleeding risk did not appear to be correlated with laboratory test results in most cases, blanket screening of NF-1 individuals for evaluation of laboratory haemostasis may not be warranted.

Outcome of children with neuromuscular disease admitted to paediatric intensive care

AIMS

To determine the outcome of children with neuromuscular disease (NMD) following admission to a tertiary referral paediatric intensive care (PICU).

METHODS

All children with chronic NMD whose first PICU admission was between July 1986 and June 2001 were followed up from their first PICU admission to time of study. The outcomes recorded were death in or outside of PICU, duration of PICU admission, artificial ventilation during admission and following discharge from PICU, and readmission to PICU.

RESULTS

Over 15 years, 28 children were admitted on 69 occasions. Sixteen (57%) children had more than one admission. The median duration of PICU admission was 4 days (range 0.5-42). Twenty three per cent of unplanned admissions resulted in the commencement of respiratory support that was continued after discharge from the PICU. Severity of functional impairment was not associated with longer duration of stay or higher PRISM scores. Ten children (36%) died, with four (14%) deaths in the PICU. A higher proportion of children with severe limitation of function were among children that died compared to survivors.

CONCLUSION

Most children with NMD admitted to the PICU recover and are discharged without the need for prolonged invasive ventilation. However, in this group of children, the use of non-invasive home based ventilation is common and they are likely to require further PICU admission.

Blood pressure and pulse responses to three stressors: associations with sociodemographic characteristics and cardiovascular risk factors

Cardiovascular reactivity is hypothesized to increase the risk of hypertension and other CVD-related conditions. However, studies to date are inconclusive. We compared the association of blood pressure and pulse responses to three stressors (postural challenge, handgrip test, mental arithmetic) with sociodemographic characteristics and CVD risk factors. We included 782 participants from the Hypertension Genetic Epidemiology Study. Blood pressure and pulse responses to stressors were defined as the difference between post- and pre-stress measurements. Stepwise regression analyses examined change in SBP and pulse in response to stressors as a function of sociodemographic and CVD risk factors. Age, race, and gender were forced into models and other variables (education, BMI, waist circumference, resting SBP and DBP, cigarette smoking, LDL and HDL cholesterol, glucose, and antihypertensive medications (beta-blockers, calcium channel blockers, diuretics, ace inhibitors)) were retained if P<0.10. Age was a significant predictor of SBP response to all stressors. The SBP response to a change in posture was not related to other variables. The SBP response to mental arithmetic was significantly higher among men, those with larger waists, higher SBP, beta-blocker users, and lower among smokers. SBP response to the handgrip was significantly higher among those with higher SBP and beta-blocker users. Similarly, the association of the pulse response to the risk factors varied considerably across the stressors. Overall, the socio-demographic and CVD risk factors accounted for between 9 and 14% of the variance in the SBP response to the stressors and from between 4 and 12% of the variance in the pulse response to the three stressors. The associations between sociodemographic and CVD risk factors and the SBP and pulse response to stress were modest and inconsistent across stressors. The findings suggest that cardiovascular reactivity is a concept that needs to be defined in reference to specific stressors so that mechanisms leading to responses can be better understood.

Aberrant monocyte prostaglandin synthase 2 (PGS2) expression in type 1 diabetes before and after disease onset

METHODS

We examined monocyte prostaglandin synthase 2 (PGS2/COX2) expression in individuals at risk for or with type 1 diabetes including: (i) 58 established type 1 and 2 diabetic patients; (ii) 34 autoantibody positive (AA+) children and adults; (iii) 164 infants and young children with insulin-dependent diabetes mellitus (IDDM) susceptibility human leukocyte antigen (HLA) alleles; and (iv) 37 healthy control individuals, over a 5-yr period.

RESULTS

Established type 1 diabetic patients (1 month to 30+ yr post-disease onset) had significantly higher PGS2 expression than healthy controls; by contrast, insulin-treated type 2 diabetic patients had significantly lower PGS2 expression than healthy controls. Longitudinal studies of AA+ subjects at risk for type 1 diabetes indicated that 73% (11/15) of individuals who developed this disease during the study period expressed high levels of PGS2 prior to or after onset. We also found high level PGS2 expression in genetically at-risk infants and young children that correlated with having a first-degree relative with type 1 diabetes, but not with age, gender, or HLA genotype. In this population, high level PGS2 expression coincided with or preceded autoantibody detection in 30% (3/10) of subjects.

CONCLUSIONS

These findings suggest that high level monocyte PGS2 expression, although subject to fluctuation, is present in at-risk subjects at an early age and is maintained during progression to and after type 1 diabetes onset.

Principal mutation hotspot for central core disease and related myopathies in the C-terminal transmembrane region of the RYR1 gene

The congenital myopathies are a group of disorders characterised by the predominance of specific histological features observed in biopsied muscle. Central core disease and nemaline myopathy are examples of congenital myopathies that have specific histological characteristics but significantly overlapping clinical pictures. Central core disease is an autosomal dominant disorder with variable penetrance which has been linked principally to the gene for the skeletal muscle calcium release channel (RYR1). Two recent reports have identified the 3' transmembrane domain of this gene as a common site for mutations. Two other studies have reported single families that have features of both central core disease and nemaline myopathy (core/rod disease) caused by mutations in RYR1. Screening of the 3' region (exons 93-105) of the RYR1 gene for mutations in 27 apparently unrelated patients with either central core disease or core/rod disease by single strand conformation polymorphism analysis and DNA sequencing identified three described and nine novel mutations in 15 patients.

Neurofibromatosis type 1

Neurofibromatosis 1 (NF1) is an autosomal dominant neurocutaneous disorder with an incidence of approximately 1 in 4000. Cognitive deficits and academic learning difficulties are the most common neurological 'complication' of NF1 in childhood and can be responsible for significant lifetime morbidity. The NF1 gene is usually classified as a tumor suppressor gene, but it is not yet known how NF1 gene mutations cause many of the non-tumor manifestations of the disorder. The NF1 protein, neurofibromin is expressed early during embryonic development with high levels of expression in the brain, suggesting that it plays an important role in regulating the orderly differentiation of central nervous system neurons. The mouse model for NF1 demonstrates behavioral abnormalities which bear striking similarity to the cognitive phenotype observed in humans with NF1. This review summarises our current understanding of the function of the NF1 gene, the nature of cognitive deficits in this disorder and correlations between neuroradiological, pathological and neuropsychological findings and animal studies which provide an insight into the pathogenesis.

Differential expression of the actin-binding proteins, alpha-actinin-2 and -3, in different species: implications for the evolution of functional redundancy

The alpha-actinins are a multigene family of four actin-binding proteins related to dystrophin. The two skeletal muscle isoforms of alpha-actinin (ACTN2 and ACTN3) are major structural components of the Z-line involved in anchoring the actin-containing thin filaments. In humans, ACTN2 is expressed in all muscle fibres, while ACTN3 expression is restricted to a subset of type 2 fibres. We have recently demonstrated that alpha-actinin-3 is absent in approximately 18% of individuals in a range of human populations, and that homozygosity for a premature stop codon (577X) accounts for most cases of true alpha-actinin-3 deficiency. Absence of alpha-actinin-3 is not associated with an obvious disease phenotype, raising the possibility that ACTN3 is functionally redundant in humans, and that alpha-actinin-2 is able to compensate for alpha-actinin-3 deficiency. We now present data concerning the expression of ACTN3 in other species. Genotyping of non-human primates indicates that the 577X null mutation has likely arisen in humans. The mouse genome contains four orthologues which all map to evolutionarily conserved syntenic regions for the four human genes. Murine Actn2 and Actn3 are differentially expressed, spatially and temporally, during embryonic development and, in contrast to humans, alpha-actinin-2 expression does not completely overlap alpha-actinin-3 in postnatal skeletal muscle, suggesting independent function. Furthermore, sequence comparison of human, mouse and chicken alpha-actinin genes demonstrates that ACTN3 has been conserved over a long period of evolutionary time, implying a constraint on evolutionary rate imposed by continued function of the gene. These observations provide a real framework in which to test theoretical models of genetic redundancy as they apply to human populations. In addition we highlight the need for caution in making conclusions about gene function from the phenotypic consequences of loss-of-function mutations in animal knockout models.

Delayed conception and active and passive smoking. The Avon Longitudinal Study of Pregnancy and Childhood Study Team

OBJECTIVE

To determine whether passive as well as active smoking by women or smoking by men is associated with delayed conception, after adjustment for confounding factors.

DESIGN

Population study of couples expecting a baby. Logistic regression was performed to identify factors associated with delayed conception.

SETTING

The Avon Health Authority area, United Kingdom.

PATIENT(S)

All couples expected to deliver between April 1991 and December 1992.

INTERVENTION(S)

Questionnaires administered early in pregnancy.

MAIN OUTCOME MEASURE(S)

Time taken to conceive, categorized as <6 months, 6-11 months, 1-3 years, and >3 years.

RESULT(S)

After correction for confounding factors, delayed conception was statistically significantly associated with both active smoking by the woman (odds ratio [OR] 1.23 [95% CI 0.98-1.49] for > 6 months and 1.54 [95% CI 1.19-2.01] for >12 months) and her exposure to passive smoking (OR 1.17 [95% CI 1.02-1.37] and 1.14 [95% CI 0.92-1.42]) compared with women with no exposure to tobacco smoke (referent). Heavy smoking by men was independently associated with delayed conception. In active smokers, the effect increased with the number of cigarettes.

CONCLUSION(S)

Smoking by men and passive and active smoking by women are associated with delayed conception.

Increasing paternal age is associated with delayed conception in a large population of fertile couples: evidence for declining fecundity in older men. The ALSPAC Study Team (Avon Longitudinal Study of Pregnancy and Childhood)

The impact of male age on fecundity remains controversial. Here, a large population study was used to investigate the effect of paternal age on time to conception. All couples in the Avon Health district expecting a baby between 1 April 1991 and 31 December 1992 were eligible. Questionnaires completed by both the man and the woman at 18 weeks gestation covered specific fertility factors, e.g. parity, paternity, cohabitation and oral contraception; and non-specific factors, e.g. educational achievement, housing, cigarette smoking, alcohol consumption, obesity. Logistic regression was used to identify factors independently related to conception in < or =6 or < or =12 months. Of 8515 planned pregnancies, 74% were conceived in < or =6 months, 14% in the second 6 months and 12% after more than a year. Nine variables, including the age of the woman, were independently related to time to conception. After adjustment for these, the likelihood of conception within 6 or 12 months was lower in older men. Compared to men <25 years old, the adjusted odds ratios (95% confidence interval) for conception in < or =12 months were 0.62 (0.40, 0.98), 0.50 (0.31, 0.81) and 0.51 (0.31, 0.86) in men aged 30-34, 35-39 and > or =40 years respectively.

Types of drinks consumed by infants at 4 and 8 months of age: a descriptive study. The ALSPAC Study Team

OBJECTIVE

To document the type and volume of drinks given to infants and investigate whether giving supplementary drinks leads to reduced milk consumption.

DESIGN

Carers were asked to record all drinks consumed by the infants in a 24-hour period at two ages, detailing the types and volume taken.

SETTING

The Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC).

SUBJECTS

A randomly chosen population sample of over 1000 infants at 4 and 8 months of age.

RESULTS

The different types of milk feed were used to group infants, compare volumes consumed and look at the use of non-milk drinks. The average volume of drinks consumed over 24 hours at 4 months was 861 ml and at 8 months was 662 ml. At 4 months 69.7% consumed infant formula and 43.0% breast milk. The mean volume of milk consumed by those having only formula was 802 ml and for those having only breast milk was estimated at 850 ml. The volumes of milks consumed were slightly lower in the groups who also had supplementary drinks. A quarter of infants were given fruit drinks and 14.6% herbal drinks. Supplementary drinks and solids were more likely to be given to formula-fed than breast-fed infants. At 8 months, formula milk was consumed by 71.4% and breast milk use had decreased (22.9%) but fruit drink use had increased (squash/cordial: 55.8%, fruit juice: 14.9%), with 13.9% of infants having no infant milk at all. More infants were fed formula milk and less were fed cows' milk compared with a nationally representative British study conducted 5 years earlier.

CONCLUSIONS

Many infants were given supplementary drinks by 4 months; there is some evidence that this led to a small reduction in milk intake. A minority were not being given infant milks at all by 8 months, contrary to British infant feeding recommendations.

A maternal vegetarian diet in pregnancy is associated with hypospadias. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

OBJECTIVE

To investigate the possible role of the maternal diet, particularly vegetarianism and consumption of phytoestrogens, in the origin of hypospadias, which is reported to be increasing in prevalence.

SUBJECTS AND METHODS

Detailed information was obtained prospectively from mothers, including previous obstetric history, lifestyle and dietary practices, using structured self-completed questionnaires during pregnancy. Previously recognized associations with environmental and parental factors were examined, focusing particularly on the hypothesized hormonal link. Multivariate logistic regression was used to identify independent associations.

RESULTS

Of 7928 boys born to mothers taking part in the Avon Longitudinal Study of Pregnancy and Childhood, 51 hypospadias cases were identified. There were no significant differences in the proportion of hypospadias cases among mothers who smoked, consumed alcohol or for any aspect of their previous reproductive history (including the number of previous pregnancies, number of miscarriages, use of the contraceptive pill, time to conception and age at menarche). Significant differences were detected for some aspects of the maternal diet, i.e. vegetarianism and iron supplementation in the first half of pregnancy. Mothers who were vegetarian in pregnancy had an adjusted odds ratio (OR) of 4.99 (95% confidence interval, CI, 2.10-11.88) of giving birth to a boy with hypospadias, compared with omnivores who did not supplement their diet with iron. Omnivores who supplemented their diet with iron had an adjusted OR of 2.07 (95% CI, 1.00-4.32). The only other statistically significant association for hypospadias was with influenza in the first 3 months of pregnancy (adjusted OR 3.19, 95% CI 1.50-6.78).

CONCLUSION

As vegetarians have a greater exposure to phytoestrogens than do omnivores, these results support the possibility that phytoestrogens have a deleterious effect on the developing male reproductive system.

Multivariate analysis of diet among three-year-old children and associations with socio-demographic characteristics. The Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) Study Team

STUDY OBJECTIVE

The study of the whole diet in combination rather than the consumption of individual food items or the intake of specific nutrients could be enlightening. This has been previously performed using principal components analysis (PCA) on adult diets but not on those of children.

DESIGN

The frequency of consumption of a range of food items was recorded for 10,139 3-y-old children by their mothers using self-completion postal questionnaires. These children form part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC).

METHODS

PCA was performed to identify individual dietary types which were then related to various socio-economic and demographic characteristics.

RESULTS

Four distinct dietary components were obtained explaining 23.5% of the total variation in the sample, and the socio-demographic characteristics of the sample were related to them. The first represented a diet based on convenience foods and was associated with younger, less educated mothers and the presence of older siblings. The second was associated with a high consumption of foods currently considered to be healthy and was particularly related to vegetarian mothers and higher education levels. The third component described the established British 'meat and two veg' diet and was associated with girls and children with no older siblings, while the fourth had high loadings for snack and finger foods and was related to socially advantaged conditions and the presence of older siblings.

CONCLUSIONS

Identifiable groups of mothers were associated with feeding their child each of the four dietary types, supporting the hypothesis that social, demographic and lifestyle factors relating to the mother have an influence on the early eating patterns of children. This analysis will form a basis for the future study of various childhood outcomes including growth, health and development.

SPONSORSHIP

University of Bristol European Journal of Clinical Nutrition (2000) 54, 73-80

Homozygosity for a nonsense mutation in the alpha-tropomyosin slow gene TPM3 in a patient with severe infantile nemaline myopathy

The nemaline myopathies are muscle disorders of variable severity and age of onset, with characteristic nemaline bodies in the sarcoplasm. Genes for dominant (NEM1) and recessive (NEM2A) nemaline myopathy have been localised to chromosomes one and two, respectively. A missense mutation in the alpha-tropomyosin gene (TPM3) has been associated with NEM1 in one family. Probands from 76 other nemaline myopathy families have now been screened for TPM3 mutations. One proband, who was not noted to have any weakness neonatally, but who died at 21 months of age, was shown to be homozygous for a single strand conformation polymorphism (SSCP) in skeletal-muscle-specific exon 1 of TPM3. Sequencing revealed homozygosity for a nonsense mutation at codon 31 (CAG to TAG). The patient should have no functioning alpha-tropomyosin slow protein. The nemaline bodies in this patient were exclusively in type one fibres, consistent with the expression of TPM3 only in type one fibres.

Does employment improve the health of lone mothers? The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

In Britain the government is currently proposing legislation that will encourage welfare recipients to gain employment. A central tenet of this 'welfare to work' policy is that employment will not only reduce the poverty of welfare recipients, but also improve their health. This research assessed the extent to which the movement from 'welfare to work' is likely to benefit the mental and physical health of lone mothers with preschool children. The sample was 719 lone mothers and a comparison group of 8779 women with partners drawn from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC). Data collected by self completion questionnaire at 33 months postpartum provided information about average weekly take home family income and the mother's employment status. The health outcomes measured were general well being, both minor and major depression (using the Edinburgh Postnatal Depression Scale), self report of respiratory symptoms (cough/cold, wheeze, influenza) from 18-33 months postpartum and self report of symptoms common in the childbearing years (backache, haemorrhoids) also from 18-33 months postpartum. Lone mothers who were not employed were the poorest group in the sample; 94% of this group (402) had a family income of less than pound sterling 200 per week, compared with 72% (188) of lone mothers who were employed, 25% (905) of partnered women who were not employed and 12% (466) of partnered women who were employed. Lone mothers were significantly more likely than women with partners to report poorer well being (chi2 = 11.7, df = 3, P = 0.01), to have a major depressive disorder (chi2 = 92.6, df = 1, P = 0.0001) and to report wheeze (chi2 = 31.1, df = 1, P = 0.0001), but significantly less likely to report cough/cold (chi2 = 9.9, df = 1, P = 0.0001) or haemorrhoids (chi2 = 16.6, df = 1, P = 0.0001). Lone mothers who were unemployed and living on less than pound sterling 100 per week were significantly more likely to be depressed (chi2 = 3.9, df = 1, P = 0.05) than those who were employed and living on pound sterling 200 or more per week, and significantly less likely to report cough/cold (chi2 = 3.8, df = 1, P = 0.05). Logistic regression analyses showed no significant independent association between employment and better health for lone mothers. Rather, when compared with lone mothers who were not working, those who were employed were more likely to report minor respiratory symptoms such as cough/cold (OR = 1.51, 95% CI = 1.00,2.31). Overall, the results suggested that the movement from 'welfare to work' is unlikely to improve the health of lone mothers.

Pertussis vaccination and wheezing illnesses in young children: prospective cohort study. The Longitudinal Study of Pregnancy and Childhood Team

OBJECTIVES

To examine the relation between pertussis vaccination and the prevalence of wheezing illnesses in young children.

DESIGN

Prospective cohort study.

SETTING

Three former health districts comprising Avon Health Authority.

SUBJECTS

9444 of 14 138 children enrolled in the Avon longitudinal study of pregnancy and childhood and for whom data on wheezing symptoms, vaccination status, and 15 environmental and biological variables were available.

MAIN OUTCOME MEASURES

Episodes of wheezing from birth to 6 months, 7-18 months, 19-30 months, and 31-42 months. These time periods were used to derive five categories of wheezing illness: early wheezing (not after 18 months); late onset wheezing (after 18 months); persistent wheezing (at every time period); recurrent wheezing (any combination of two or more episodes for each period); and intermittent wheezing (any combination of single episodes of reported wheezing). These categories were stratified according to parental self reported asthma or allergy.

RESULTS

Unadjusted comparisons of the defined wheezing illnesses in vaccinated and non-vaccinated children showed no significant association between pertussis vaccination and any of the wheezing outcomes regardless of stratification for parental asthma or allergy. Wheeze was more common in non-vaccinated children at 18 months, and there was a tendency for late onset wheezing to be associated with non-vaccination in children whose parents did not have asthma, but this was not significant. After adjustment for environmental and biological variables, logistic regression analyses showed no significant increased relative risk for any of the wheezing outcomes in vaccinated children: early wheezing (0.99, 95% confidence interval 0.80 to 1.23), late onset wheezing (0.85, 0.69 to 1.05), persistent wheezing (0.91, 0.47 to 1.79), recurrent wheezing (0.96, 0.72 to 1.26), and intermittent wheezing (1.06, 0.81 to 1.37).

CONCLUSIONS

No evidence was found that pertussis vaccination increases the risk of wheezing illnesses in young children. Further follow up of this population with objective measurement of allergy and bronchial responsiveness is planned to confirm these observations.

Pacifier use and morbidity in the first six months of life

OBJECTIVE

To assess the prevalence of pacifier use and whether this habit adversely affects the health of 6-month-old infants.

DESIGN

Data collected via self-completion questionnaires from mothers forming part of the prospective, population-based Avon Longitudinal Study of Pregnancy and Childhood.

METHODS

The mothers of 10 950 infants gave information on their child's use of a pacifier at 4 weeks and 6 months of age and the presence of specific health symptoms. Adjusted logistic regression was performed to identify any associations between pacifier use and ill health.

RESULTS

Two thirds of the sample had been given a pacifier at some point, with 42% being reported as having one at both ages. Younger, lower educated mothers, mothers who smoked, those living in council and overcrowded accommodation, and those reporting financial difficulties were significantly more likely to give their infant a pacifier. Pacifier use was associated significantly with a higher risk of symptoms such as wheezing, earache, vomiting, fever, diarrhea, and colic as well as with the general practitioner being called to the home and hospital admission.

CONCLUSIONS

Although significant differences exist in the risk of experiencing several health symptoms between infants who do and infants who do not use a pacifier, stronger and more detailed evidence is required before recommendations can be made to discourage the use of pacifiers based purely on reducing occurrences of these symptoms.

Neurofibromatosis of the small intestine mesentery in a child with neurofibromatosis type 1

The authors present a case of mesenteric neurofibromatosis in a child, which is a rare complication of neurofibromatosis type 1 (NF1). This case is presented to illustrate the clinical features and the radiological appearance of mesenteric neurofibromatosis, which, in the appropriate clinical setting of NF1, are diagnostic. The authors also discuss the long-term complications of this condition, which includes the potential risk of malignant degeneration.

Oxidative phosphorylation defect associated with primary adrenal insufficiency

An 18-month-old girl with an oxidative phosphorylation defect had neonatal onset of chronic lactic acidosis, lipid storage myopathy, bilateral cataracts, and primary adrenal insufficiency. Chronic lactic acidosis responded to treatment with dichloroacetate. Sequential muscle biopsies demonstrated resolution of the lipid storage myopathy associated with the return to normal muscle free carnitine levels. This case demonstrates a new clinical phenotype associated with a defect in oxidative phosphorylation and the need to consider mitochondrial disorders in the differential diagnosis of primary adrenal insufficiency in childhood.

Bilateral infantile cataractogenesis in a patient with deficiency of complex I, a mitochondrial electron transport chain enzyme

Progressive bilateral cataracts developed in infancy in a 5-month-old girl with deficiency of complex I, a mitochondrial electron transport chain enzyme. In the newborn period, she had severe lactic acidosis and the diagnosis of complex I deficiency was confirmed by mitochondrial respiratory chain assay on muscle biopsy. By 5 months, she had completely opaque nuclear sclerotic cataracts, with loss of fixation and the red reflex. She underwent bilateral, sequential cataract extraction. The lens aspirate was submitted for cytologic analysis and electron microscopy, which revealed increased intracellular glycogen and swollen mitochondria. To our knowledge the association of complex I deficiency with cataracts in infancy has not been reported previously. The diagnosis of a respiratory chain enzyme defect in infancy is an indication for early ophthalmic evaluation to identify cataracts that may result in visual loss. Conversely, the recognition of cataracts in infants with unexplained neurologic disease or metabolic acidosis may necessitate further evaluation for metabolic etiologies, including mitochondrial disorders.