Background The emergence of Zika virus (ZIKV) in the Americas has coincided with an increase in the report of birth of infants with microcephaly. On 1 February 2016, the World Health Organization declared the suspected link between ZIKV and microcephaly a Public Health Emergency of International Concern. However, to date, precise quantification of this association is lacking. Methods We retrospectively analysed data from a ZIKV outbreak in French Polynesia in October 2013–April 2014, which was the largest ever documented prior to the outbreak in the Americas. Serological and surveillance data were used to estimate the probability of ZIKV infection for each week of the epidemic. We also conducted an exhaustive search of medical records to identify all microcephaly cases from September 2013–July 2015. Simple models were developed to determine the period during pregnancy when ZIKV infection may increase the risk of microcephaly and estimate the associated risk. Findings Sixty-six percent (95% CI: 62, 70) of Polynesians were infected by ZIKV. Of the eight microcephaly cases identified during the 23-month study period, seven (88%) occurred in the four-month period following the ZIKV outbreak. This pattern was best explained by a model that assumed ZIKV infection in the first trimester of pregnancy increased the risk of microcephaly. In this model, the risk of microcephaly associated with ZIKV infection was 95 (95 CI: 34, 191) per 10,000 women infected in the first trimester of pregnancy while the prevalence of microcephaly was 2 (95% CI: 0, 8) per 10,000 neonates. Models where the risk of microcephaly also increased if infection occurred in trimesters 2 and 3 were not significantly worse fitting than this model. Interpretation This study provides the first quantitative estimate of the risk of microcephaly in a foetus/neonate whose mother was infected by ZIKV. Funding Labex-IBEID, NIH-MIDAS, AXA Research fund and EU-PREDEMICS.

Pierre Robin sequence (PRS) is an important subgroup of cleft palate. We report several lines of evidence for the existence of a 17q24 locus underlying PRS, including linkage analysis results, a clustering of translocation breakpoints 1.06-1.23 Mb upstream of SOX9, and microdeletions both approximately 1.5 Mb centromeric and approximately 1.5 Mb telomeric of SOX9. We have also identified a heterozygous point mutation in an evolutionarily conserved region of DNA with in vitro and in vivo features of a developmental enhancer. This enhancer is centromeric to the breakpoint cluster and maps within one of the microdeletion regions. The mutation abrogates the in vitro enhancer function and alters binding of the transcription factor MSX1 as compared to the wild-type sequence. In the developing mouse mandible, the 3-Mb region bounded by the microdeletions shows a regionally specific chromatin decompaction in cells expressing Sox9. Some cases of PRS may thus result from developmental misexpression of SOX9 due to disruption of very-long-range cis-regulatory elements.

The acronym CHARGE refers to a syndrome of unknown cause. Here we report on 47 CHARGE patients evaluated for the frequency of major anomalies, namely coloboma (79%), heart malformation (85%), choanal atresia (57%), growth and/or mental retardation (100%), genital anomalies (34%), ear anomalies (91%), and/or deafness (62%). In addition, we comment on anomalies observed very frequently in neonates and infants with the CHARGE syndrome, including, minor facial anomalies, neonatal brain stem dysfunction with cranial nerve palsy, and, mostly, internal ear anomalies such as semicircular canal hypoplasia that were found in each patient that could be tested. We propose several criteria for poor survival including male gender, central nervous system and/or oesophageal malformations, and bilateral choanal atresia. No predictive factor regarding developmental prognosis could be identified in our series. A significantly higher mean paternal age at conception together with concordance in monozygotic twins and the existence of rare familial cases support the role of genetic factors such as de novo mutation of a dominant gene or subtle sub-microscopic chromosome rearrangement. Finally, the combination of malformations in CHARGE syndrome strongly supports the view that this multiple congenital anomalies/mental retardation syndrome is a polytopic developmental field defect involving the neural tube and the neural crests cells.

We detected an unusual increase in congenital cerebral malformations and dysfunction in fetuses and newborns in French Polynesia, following an epidemic of Zika virus (ZIKV), from October 2013 to March 2014. A retrospective review identified 19 cases, including eight with major brain lesions and severe microcephaly, six with severe cerebral lesions without microcephaly and five with brainstem dysfunction without visible malformations. Imaging revealed profound neurological lesions (septal and callosal disruption, ventriculomegaly, abnormal neuronal migration, cerebellar hypoplasia, occipital pseudocysts, brain calcifications). Amniotic fluid was drawn from seven cases at gestation weeks 20 to 29. ZIKV RNA was detected by RT-PCR and infectious ZIKV isolates were obtained in four of five microcephalic, but not in two non-microcephalic cases with severe brain lesions. Medical termination of pregnancy was performed in eleven cases; two cases with brainstem dysfunction died in the first months of life; six cases are alive, with severe neurological impairment. The results show that four of seven tested fetuses with major neurological injuries were infected with ZIKV in utero. For other non-microcephalic, congenital abnormalities we were not able to prove or exclude ZIKV infection retrospectively. The unusual occurrence of brain malformations or dysfunction without microcephaly following a ZIKV outbreak needs further studies.

IMPORTANCE Robin sequence (RS) is a congenital condition characterized by micrognathia, glossoptosis, and upper airway obstruction. Currently, no consensus exists regarding the diagnosis and evaluation of children with RS. An international, multidisciplinary consensus group was formed to begin to overcome this limitation. OBJECTIVE To report a consensus-derived set of best practices for the diagnosis and evaluation of infants with RS as a starting point for defining standards and management. EVIDENCE REVIEW Based on a literature review and expert opinion, a clinical consensus report was generated. FINDINGS Because RS can occur as an isolated condition or as part of a syndrome or multiple-anomaly disorder, the diagnostic process for each newborn may differ. Micrognathia is hypothesized as the initiating event, but the diagnosis of micrognathia is subjective. Glossoptosis and upper airway compromise complete the primary characteristics of RS. It can be difficult to judge the severity of tongue base airway obstruction, and the possibility of multilevel obstruction exists. The initial assessment of the clinical features and severity of respiratory distress is important and has practical implications. Signs of upper airway obstruction can be intermittent and are more likely to be present when the infant is asleep. Therefore, sleep studies are recommended. Feeding problems are common and may be exacerbated by the presence of a cleft palate. The clinical features and their severity can vary widely and ultimately dictate the required investigations and treatments. CONCLUSIONS AND RELEVANCE Agreed-on recommendations for the initial evaluation of RS and clinical descriptors are provided in this consensus report. Researchers and clinicians will ideally use uniform definitions and comparable assessments. Prospective studies and the standard application of validated assessments are needed to build an evidence base guiding standards of care for infants and children with RS.