Introduction: The recent Zika virus(ZIKV) epidemic in Brazil was characterized by a range of different clinical presentations, particularly microcephaly, Guillain-Barré syndrome, and death. In this context, we determined the causal relationship between fatal microcephaly cases and ZIKV infection. Methods: Twelve fatal cases of neonates, whose mothers were infected with ZIKV during pregnancy, were examined; cases included nine neonatal deaths due to microcephaly, one miscarriage, and two stillbirths. Tissue samples were obtained from all cases at necropsy and were submitted for virological investigation (RT-qPCR and virus isolation) and/or histopathology (hematoxylin and eosin staining) and immunohistochemical assay for the detection of ZIKV antigens. Results: ZIKV antigens and/or ZIKV RNA were detected in tissue samples of all 12 cases examined. ZIKV was recovered in one case. Results of the virological and immunohistochemical analyses, as well as the anatomic abnormalities and histopathologic changes observed at necropsy on the 12 fatal cases, are presented. Conclusions: Data from these 12 cases provide strong evidence of the causal relationship between ZIKV and congenital disease in fetuses of women who were infected with the virus during pregnancy.

Pycnodysostosis is an autosomal recessive skeletal dysplasia, the prevalence of which is estimated to be low (1 per million). Nevertheless, in recent years we have found 27 affected individuals from 22 families in Ceará State, a region of the Brazilian Northeast, giving a local prevalence of 3 per million. This local prevalence associated with a high parental consanguinity, suggesting a possible founder effect, prompted us to perform a molecular investigation of these families to test this hypothesis. The CTSK gene was sequenced by the Sanger method in the patients and their parents. In addition to 18 families from Ceará, this study also included 15 families from other Brazilian regions. We also investigated the origin of each family from the birthplace of the parents and/or grandparents. We have studied 39 patients, including 33 probands and 6 sibs, from 33 families with pycnodysostosis and identified six mutations, five previously described (c.436G>C, c.580G>A, c.721C>T, c.830C>T and c.953G>A) and one novel frameshift (c.83dupT). This frameshift variant seems to have a single origin in Ceará State, since the haplotype study using the polymorphic markers D1S2344, D1S442, D1S498 and D1S2715 suggested a common origin. Most of the mutations were found in homozygosity in the patients from Ceará (83.3 %) while in other states the mutations were found in homozygosity in half of patients. We have also shown that most of the families currently living outside of Ceará have northeastern ancestors, suggesting a dispersion of these mutations from the Brazilian Northeast. The high frequency of pycnodysostosis in Ceará State is the consequence of the high inbreeding in that region. Several mutations, probably introduced a long time ago in Ceará, must have spread due to consanguineous marriages and internal population migration. However, the novel mutation seems to have a single origin in Ceará, suggestive of a founder effect.

Accumulation of phenylalanine (Phe) due to deficiency in the enzyme phenylalanine hydroxylase (PAH), responsible for the conversion of Phe into tyrosine leads to Phenylketonuria (PKU), a rare autosomal recessive inborn error of metabolism with a mean prevalence of approximately 1:10,000 to 1:15,000 newborns. Physical, neurocognitive and psychiatric symptoms include neurodevelopmental disorder as intellectual disability and autism spectrum disorder. The most common treatments such as low-Phe diet and supplements may decrease blood Phe concentrations, but neuropsychological, behavioral and social issues still occur in some patients. This study aimed to better understand (i) the Brazilian population's knowledge about newborn screening (NBS), the main diagnostic method for PKU, as well as (ii) the impacts of phenylketonuria in the daily lives of patients and parents. Two surveys in Real World Data format gathering of Brazilian residents by online questionnaires with (i) 1000 parents of children up to 5 years old between March and April 2019; (ii) 228 PKU patients and caregivers in March 2019. The survey was conducted in partnership with Abril Publisher and two Brazilian patient associations: Metabolic Mothers and SAFE Brasil, for families with rare diseases and PKU patients, respectively. The first questionnaire shows that 93% of parents recognize the importance of NBS and 92% report that their children have undergone the test. Still, two out of ten participants did not know what the exam is or what it is for. From the second questionnaire nine out of ten patients had their PKU diagnosis by NBS. Although strict dietary controls for PKU were claimed by 44% of respondents from second questionnaire, 55% assume not following all nutritionist recommendations and 52% did not maintain routinely Phe control levels. In addition, 53% said they had high spending on medical appointments, therapies and purchase of special foods. Despite the lack of understanding, the awareness of NBS importance is present in the studied population. The early diagnosis of most PKU patients in the study corroborates with neonatal screening central role of PKU early detection. The difficulty in adhering to dietary adjustments and the possibility that current and new therapeutic strategies other than diet could be determinant to achieve the recommended Phe levels.