Repetitive stress fracture: a warning sign of genetic susceptibility to fracture? A case report of a heterozygous variant in SERPINF1

SUMMARY The occurrence of fractures in young individuals is frequently overlooked by physicians, especially when associated with exercise or trauma. Nevertheless, multiple fractures should always be investigated since underlying conditions can predispose to such events. We describe here the case of a young, healthy woman who sustained multiple fractures in the lower limbs, which were initially considered to be "stress fractures". Further investigation, including a panel of genes associated with osteogenesis imperfecta, revealed that the patient is a heterozygous carrier of a SERPINF1 variant. According to criteria recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, this variant is classified as likely benign (PM2, PP3, PP4, BP1, and BP4). The patient's mother and brother were also asymptomatic carriers of the variant and had sustained previous minor fractures. The patient had normal biochemical profile and bone density. This condition has been rarely described and is not associated with low bone mineral density or altered bone turnover markers. This case highlights the importance of investigating multiple fractures in young patients who are otherwise healthy since these may be a warning sign of rare genetic conditions associated with fragility fractures.

The first five-year evaluation of cystic fibrosis neonatal screening program in São Paulo State, Brazil / Uma avaliação dos primeiros cinco anos do programa de triagem neonatal da fibrose cística no Estado de São Paulo, Brasil / Una evaluación de los primeros cinco años del programa de cribado neonatal de fibrosis cística en el Estado de São Paulo, Brasil

The Hospital of the Ribeirão Preto Medical School, University of São Paulo is one of the three screening centers in São Paulo State, Brazil, and has included a test for cystic fibrosis (CF) since February 6, 2010, by a court order. We evaluated the first five years of this CF-newborn screening program. The original immunoreactive trypsinogen (IRT)/IRT screening protocol was adopted in Brazil. A total of 173,571 newborns were screened, 1,922 (1.1%) of whom showed IRT1 ≥ 70ng/mL. Of these, 1,795 (93.4%) collected IRT2, with elevated results (IRT2 ≥ 70ng/mL) in 102 of them (5.2%). We identified a total of 26 CF cases during this period, including three CF cases that were not detected by the CF-newborn screening. The incidence of the disease among the screened babies was 1:6,675 newborns screened. Median age at the initial evaluation was 42 days, comparable to that of neonates screened with the IRT/DNA protocol. Almost all infants with CF already exhibited some manifestations of the disease during the neonatal period. The mutation most frequently detected in the CF cases was F508del. These findings suggest the early age at the beginning of treatment at our center was due to the effort of the persons involved in the program regarding an effective active search. Considering the false negative results of CF-newborn screening and the early onset of clinical manifestations of the disease in this study, pediatricians should be aware of the diagnosis of CF even in children with negative test.

O Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo é um dos três centros de triagem da fibrose cística (FC) no estado de São Paulo, tendo incluído esse teste desde 6 de fevereiro de 2010, a partir de uma liminar judicial. O estudo avalia os primeiros cinco anos desse programa de triagem neonatal da FC. O Brasil adota o protocolo de triagem original, com o tripsinogênio imunorreativo (IRT)/IRT. Foram triados um total de 173.571 recém-nascidos, dos quais 1.922 (1,1%) mostraram IRT ≥ 70ng/mL. Destes, 1.795 (93,4%) tiveram amostras coletadas para IRT2, com resultados elevados (IRT2 ≥ 70ng/mL) em 102 deles (5,2%). Identificamos um total de 26 casos de FC durante esse período, inclusive 3 casos de FC que não foram detectados com a triagem neonatal. A incidência da FC foi de 1 caso em cada 6.675 recém-nascidos triados. A idade mediana na avaliação inicial foi 42 dias, comparável à idade de recém-nascidos triados com o protocolo IRT/DNA. Quase todos os lactentes com FC já exibiam algumas manifestações da doença durante o período neonatal. A mutação mais comum nos casos de FC foi a F508del. Os resultados em nosso centro indicam que a idade precoce no início do tratamento foi devido aos esforços do programa na implementação de uma busca ativa eficaz. Considerando os resultados falsos-negativos no programa de triagem neonatal para FC e o início precoce das manifestações clínicas da doença neste estudo, os pediatras devem estar cientes da possibilidade de diagnóstico de FC, mesmo em crianças com teste negativo.

El Hospital das Clínicas de la Facultad de Medicina de Ribeirão Preto, São Paulo Universidad es uno de los tres centros de cribado de fibrosis cística (FC) en el estado de São Paulo, incluyendo este test desde el 6 de febrero de 2010, debido a una medida cautelar judicial. El estudio evalúa los primeros cinco años de este programa de cribado neonatal de FC. Brasil adopta el protocolo de cribado original, con el tripsinógeno inmunorreactivo (TIR)/IRT. Se cribaron un total de 173.571 recién nacidos, de los cuales 1.922 (1,1%) mostraron IRT ≥ 70ng/mL. De estos, se obtuvieron 1.795 (93,4%) muestras recogidas para IRT2, con resultados elevados (IRT2 ≥ 70ng/mL) en 102 de ellos (5,2%). Identificamos un total de 26 casos de FC durante ese período, inclusive 3 casos de FC que no fueron detectados con el cribado neonatal. La incidencia de la FC fue de 1 caso por cada 6.675 recién-nacidos cribados. La edad media en la evaluación inicial fue 42 días, comparable a la edad de recién nacidos cribados con el protocolo IRT/DNA. Casi todos los lactantes con FC ya manifestaban algunos síntomas de la enfermedad durante el período neonatal. La mutación más común en los casos de FC era el F508del. Los resultados en nuestro centro indican que la edad precoz en el inicio del tratamiento se debía a los esfuerzos del programa en la implementación de una búsqueda activa eficaz. Considerando los resultados falsos-negativos en el programa de cribado neonatal para FC, y el inicio precoz de las manifestaciones clínicas de la enfermedad en este estudio, los pediatras deben ser conscientes de la posibilidad de diagnóstico de FC, incluso en niños con test negativo.

Clinical-neurologic, cytogenetic and molecular aspects of the Prader-Willi and Angelman syndromes

The Prader-Willi syndrome (PWS) and the Angelman syndrome (AS) are human neurogenetic disorders involving the imprinting mechanism, at the 15q11-13 chromosome region. The predominant genetic defects in PW are 15q11-13 deletions of paternal origin and maternal chromosome 15 uniparental disomy. In contrast, maternal deletions and paternal chromosome 15 uniparental disomy are associated with a different neurogenetic disorder, the AS. In both disorders, these mutations are associated with parent-of-origin specific methylation at several 15q11-13 loci. We studied 5 patients suspect of PWS and 4 patients suspect of AS who were referred to the Medical Genetics Unit at the Universsity Hospital of Medical School from Ribeirao Preto. Our objective was to establish the correct clinical and etiological diagnosis in these cases. We used conventional cytogenetics, methylation analysis with the probe KB17 (CpG island of the SNRPN gene) by Southern blotting after digestion with the Xba I and Not I restriction enzymes. We studied in patients and their parents the segregation of the (CA)(n) repeats polymorphisms by PCR, using the primers 196 and IR4-3R. All the patients had normal conventional cytogenetical analysis. We confirmed 3 cases of PWS: one by de novo deletion, one by maternal chromosome 15 uniparental disomy and one case with no defined cause determined by the used primers. We confirmed 2 cases of AS, caused by de novo deletion at the 15q11-13 region, and one case with normal molecular analysis but with strong clinical characteristics.

Estudo clínico, citogenético e molecular nas síndromes de Prader-Willi e Angelman / Clinical, cytogenetical and molecular studies in Prader-Willi and Angelman syndromes

A Síndrome de Prader-Willi (SPW) e a Síndrome de Angelman (SA) säo doenças neurogenéticas consideradas como exemplos do fenômeno de impressäo genômica, em seres humano, estando relacionadas com alteraçöes envolvendo a regiäo cromossômica 15q11-13. As alteraçöes genéticas predominantes, na SPW, säo deleçöes na regiäo 15q11-13, de origem paterna e dissomia uniparental materna e, na SA, encontram-se deleçöes na regiäo 15q11-13 materna e dissomia uniparental paterna. Estudamos 5 pacientes com suspeita clínica de SPW e 4 pacientes com suspeita clínica de SA, atendidos no Setor de Genética Médica do Hospital das Clínicas da FMRP-USP, com o objetivo de estabelecer o diagnóstico clínico e etiológico nessa amostra. Para isso, utilizamos citogenética convencional, estudo de metilaçäo por Southern blotting com a sonda KB17 (ilha CpG do gene SNRPN), após digestäo com as enzimas de restriçäo Xba I e Not I, e análise de polimorfismos de repetiçäo (CA)n por PCR, usando os primers 196 e IR4-3R. Dos 9 pacientes avaliados, todos tiveram avaliaçäo citogenética convencional normal. Foram confirmados molecularmente 1 caso de SPW por deleçäo nova, 1 caso de SPW por dissomia uniparenteal materna e 1 caso de SPW em que a causa genética näo pode ser esclarecida pela análise de polimorfismo com os primers usados. Foram confirmados, molecularmente, 2 casos de SA, ambos por deleçäo nova na regiäo 15q11-13 e, 1 caso de SA, cuja clínica é extremamente sugestiva, teve resultado molecular normal, podendo-se sugerir uma mutaçäo de ponto no gene responsável pela SA.