TP53 p.R337H is a conditional cancer-predisposing mutation: further evidence from a homozygous patient.

BACKGROUND: Adrenocortical carcinomas (ACCs) are among the most common childhood cancers occurring in infants affected with the Li-Fraumeni and Li- Fraumeni-like (LFS/LFL) syndromes, which are caused by dominant germline mutations in the TP53 gene. In Brazil, a particular mutation, occurring in the tetramerisation domain of the gene, p.R337H, is exceedingly common due to a founder effect and is strongly associated with ACC. In this report, we describe the phenotype and long-term clinical follow-up of a female child diagnosed with ACC and homozygous for the TP53 p.R337H founder mutation. CASE PRESENTATION: At age 11 months, the patient was diagnosed with a virilising anaplastic adrenal cortical tumour, which was completely excised without disturbing the adrenal capsule. Family history was consistent with an LFL tumour pattern, and genotyping identified the TP53 p.R337H mutation in both alleles in genomic DNA from lymphocytes and fibroblasts. Haplotype analysis confirmed the occurrence of the mutation in the same founder haplotype previously described in other Brazilian patients. No other germline or somatic TP53 mutations or rearrangements were identified. At age 9 years, the child was asymptomatic and had no evidence of endocrine derangements. Full body and brain magnetic resonance imaging (MRI) failed to detect any suspicious proliferative lesions, and cardiopulmonary exercise testing results were within the normal reference for the child's age, ruling out a major exercise capacity deficiency. CONCLUSION: This is the first clinical and aerobic functional capacity documentation of a patient who carries two mutant TP53 alleles and no wild-type allele. Our results support the hypothesis that TP53 p.R337H, the most common TP53 mutation ever described in any population, is a conditional mutant. Furthermore, our observations over a long period of clinical follow-up suggest that TP53 p.R337H homozygotes do not have a more severe disease phenotype than do heterozygote carriers of the same mutation. Patients with the homozygous TP53 p.R337H genotype will require careful surveillance for lifetime cancer risk and for effects on metabolic capacity later in life.

Synchronous Periampullary Tumors in a Patient With Pancreas Divisum and Neurofibromatosis Type 1.

INTRODUCTION: In this study, we describe for the first time a Neurofibromatosis type 1 patient with pancreas divisum, multiple periampullary tumors and germline pathogenic variants in NF1 and CFTR genes. CASE REPORT: A 62-year-old female NF1 patient presented with weakness, choluria, nausea, and diffuse abdominal pain to an emergency room service. Magnetic resonance imaging revealed an abdominal mass involving the periampullary region and pancreas divisum. After surgical resection, three synchronous neoplasms were detected including two ampullary tumors (adenocarcinoma of the major ampulla and a neuroendocrine tumor of the minor ampulla) and a gastrointestinal stromal tumor (GIST). Germline multigene panel testing (MGPT) identified two pathogenic heterozygous germline variants: NF1 c.838del and CFTR c.1210-34TG[12]T[5]. CONCLUSION: This is the first report of a Neurofibromatosis type 1 patient with pancreas divisum and multiple periampullary tumors harboring pathogenic germline variants in NF1 and CFTR genes. The identification of two germline variants and a developmental anomaly in this patient may explain the unusual and more severe findings and underscores the importance of comprehensive molecular analyses in patients with complex phenotypes.

Maple syrup urine disease in Brazil: a panorama of the last two decades / Doença da urina de xarope de bordo no Brasil: um panorama das últimas duas décadas

OBJECTIVE: To characterize a sample of Brazilian patients with maple syrup urine disease (MSUD) diagnosed between 1992 and 2011. METHODS: In this retrospective study, patients were identified through a national reference laboratory for the diagnosis of MSUD and through contact with other medical genetics services across Brazil. Data were collected by means of a chart review. RESULTS: Eighty-three patients from 75 families were enrolled in the study (median age, 3 years; interquartile range [IQR], 0.57-7). Median age at onset of symptoms was 10 days (IQR 5-30), whereas median age at diagnosis was 60 days (IQR 29-240, p = 0.001). Only three (3.6%) patients were diagnosed before the onset of clinical manifestations. A comparison between patients with (n = 12) and without (n = 71) an early diagnosis shows that early diagnosis is associated with the presence of positive family history and decreased prevalence of clinical manifestations at the time of diagnosis, but not with a better outcome. Overall, 98.8% of patients have some psychomotor or neurodevelopmental delay. CONCLUSION: In Brazil, patients with MSUD are usually diagnosed late and exhibit neurological involvement and poor survival even with early diagnosis. We suggest that specific public policies for diagnosis and treatment of MSUD should be developed and implemented in the country. .

OBJETIVO: Caracterizar uma amostra de pacientes brasileiros com a doença da urina de xarope de bordo (DXB) diagnosticados entre 1992 e 2011. MÉTODOS: Os pacientes foram identificados por meio de um laboratório de referência nacional para o diagnóstico de DXB e por meio do contato com outros serviços de genética médica no Brasil. Os dados foram coletados por meio de uma revisão de prontuários. RESULTADOS: Foram incluídos no estudo 83 pacientes de 75 famílias (idade média: três anos; intervalo interquartil (IQR): 0,57-7). A idade média no surgimento dos sintomas era de 10 dias (IQR: 5-30), ao passo que a idade média no diagnóstico era de 60 dias (IQR: 29-240; p = 0,001). Somente três (3,6%) pacientes foram diagnosticados antes do surgimento de manifestações clínicas. Uma comparação entre pacientes com (n = 12) e sem (n = 71) um diagnóstico precoce mostra que o diagnóstico precoce está associado à presença de histórico familiar positivo e à redução na prevalência de manifestações clínicas no momento do diagnóstico, porém sem melhor resultado. Em geral, 98,8% dos pacientes têm algum atraso no desenvolvimento psicomotor ou neurológico. CONCLUSÃO: No Brasil, os pacientes com DXB normalmente recebem um diagnóstico tardio e exibem um envolvimento neurológico e baixa sobrevivência, mesmo com um diagnóstico precoce. Sugerimos que políticas públicas específicas para o diagnóstico e tratamento da DXB sejam desenvolvidas e implementadas no país. .

Population prevalence of hereditary breast cancer phenotypes and implementation of a genetic cancer risk assessment program in southern Brazil.

In 2004, a population-based cohort (the Núcleo Mama Porto Alegre - NMPOA Cohort) was started in Porto Alegre, southern Brazil and within that cohort, a hereditary breast cancer study was initiated, aiming to determine the prevalence of hereditary breast cancer phenotypes and evaluate acceptance of a genetic cancer risk assessment (GCRA) program. Women from that cohort who reported a positive family history of cancer were referred to GCRA. Of the 9218 women enrolled, 1286 (13.9%) reported a family history of cancer. Of the 902 women who attended GCRA, 55 (8%) had an estimated lifetime risk of breast cancer ≥ 20% and 214 (23.7%) had pedigrees suggestive of a breast cancer predisposition syndrome; an unexpectedly high number of these fulfilled criteria for Li-Fraumeni-like syndrome (122 families, 66.7%). The overall prevalence of a hereditary breast cancer phenotype was 6.2% (95%CI: 5.67-6.65). These findings identified a problem of significant magnitude in the region and indicate that genetic cancer risk evaluation should be undertaken in a considerable proportion of the women from this community. The large proportion of women who attended GCRA (72.3%) indicates that the program was well-accepted by the community, regardless of the potential cultural, economic and social barriers.

Population prevalence of hereditary breast cancer phenotypes and implementation of a genetic cancer risk assessment program in southern Brazil

In 2004, a population-based cohort (the Núcleo Mama Porto Alegre - NMPOA Cohort) was started in Porto Alegre, southern Brazil and within that cohort, a hereditary breast cancer study was initiated, aiming to determine the prevalence of hereditary breast cancer phenotypes and evaluate acceptance of a genetic cancer risk assessment (GCRA) program. Women from that cohort who reported a positive family history of cancer were referred to GCRA. Of the 9218 women enrolled, 1286 (13.9 percent) reported a family history of cancer. Of the 902 women who attended GCRA, 55 (8 percent) had an estimated lifetime risk of breast cancer ³ 20 percent and 214 (23.7 percent) had pedigrees suggestive of a breast cancer predisposition syndrome; an unexpectedly high number of these fulfilled criteria for Li-Fraumeni-like syndrome (122 families, 66.7 percent). The overall prevalence of a hereditary breast cancer phenotype was 6.2 percent (95 percentCI: 5.67-6.65). These findings identified a problem of significant magnitude in the region and indicate that genetic cancer risk evaluation should be undertaken in a considerable proportion of the women from this community. The large proportion of women who attended GCRA (72.3 percent) indicates that the program was well-accepted by the community, regardless of the potential cultural, economic and social barriers.