What are the benefits of having a village? Effects of allomaternal care on communicative skills in early infancy

This study investigates whether exposure to allomaternal care (AMC-care for infants from individuals other than the mother) improves rates of communicative behaviors during late infancy by providing more opportunities to practice communicating with varied caregivers. Data were collected from 102 typically-developing infants aged 13-18 months and their mothers. AMC variables were collected using a current care questionnaire, structured 14-day diary, and longitudinal interview. Communicative behaviors were assessed through post hoc microcoding of in-lab administrations of the Early Social Communication Scales (ESCS), as well as additional microcoding of the Bayley III Screening Cognitive Subtest. Demographic covariates were also included. For each communicative behavior, backward model selection was used to determine the best fitting linear regression model. Results suggested that rates of turn-taking decreased with Household AMC (p < 0.008), but increased with two or more siblings present at home (p < 0.01). Conversely, rates of spontaneous giving increased with Household AMC (p < 0.003) regardless of the presence of siblings. Notably, exposure to more AMC was neither helpful nor harmful for many of the tested communicative behaviors, although the number of siblings present was significantly related to rates of following commands, as well as pointing and reaching. Ultimately, this study suggests that household level experiences with AMC, rather than formalized care, impact the development of some communicative behaviors during late infancy.

Electrophysiological verification of enhanced S-cone syndrome caused by a novel c.755T>C NR2E3 missense variant

BACKGROUND

Nuclear hormone receptor gene, NR2E3, plays a critical role in retinogenesis and determination of the rod photoreceptor phenotype. Mutations in NR2E3 typically lead to recessive enhanced S-cone syndrome (ESCS), where affected individuals show higher sensitivity to short wavelength light and early onset rod dysfunction. Patients with ESCS present in early childhood with nyctalopia, enhanced sensitivity to blue light and display a very heterogeneic retinal phenotype with varying degrees of clumped pigmentation and occasional retinoschisis.

PURPOSE

To confirm the pathogenicity of a novel mutation in NR2E3 using electrophysiological studies.

MATERIALS AND METHODS

Patient underwent detailed clinical evaluation and ophthalmic imaging followed by next generation sequencing analysis and electrophysiological studies.

RESULTS

We describe a case of a young man of Greek descent with a family history of retinal degeneration. His fundal features at presentation were atypical of ESCS, with striking macular involvement in both eyes, including fibrotic subretinal material overlying the pigment epithelial detachment in one eye and schisis in the other. Genetic testing revealed a novel homozygous variant in NR2E3 gene of uncertain pathogenicity. Instead of performing further genetic analyses, electrophysiological studies showed pathognomonic changes in the S-cone response.

CONCLUSIONS

With the recent clinical endorsement of a gene therapy for RPE65 related-inherited retinal degeneration it is of paramount importance to correctly identify the pathogenic genetic mutation. In this particular syndrome, we highlight the value of electrophysiology to confirm the pathogenicity of a novel mutation in NR2E3 and aid the diagnosis of ESCS, with potential for gene therapy in the future.