Over the first years of life, the brain undergoes substantial organization in response to environmental stimulation. In a silent world, it may promote vision by (i) recruiting resources from the auditory cortex and (ii) making the visual cortex more efficient. It is unclear when such changes occur and how adaptive they are, questions that children with cochlear implants can help address.
View Article and Find Full Text PDFSensory deprivation can offset the balance of audio versus visual information in multimodal processing. Such a phenomenon could persist for children born deaf, even after they receive cochlear implants (CIs), and could potentially explain why one modality is given priority over the other. Here, we recorded cortical responses to a single speaker uttering two syllables, presented in audio-only (A), visual-only (V), and audio-visual (AV) modes.
View Article and Find Full Text PDFAuditory-motor and visual-motor networks are often coupled in daily activities, such as when listening to music and dancing; but these networks are known to be highly malleable as a function of sensory input. Thus, congenital deafness may modify neural activities within the connections between the motor, auditory, and visual cortices. Here, we investigated whether the cortical responses of children with cochlear implants (CI) to a simple and repetitive motor task would differ from that of children with typical hearing (TH) and we sought to understand whether this response related to their language development.
View Article and Find Full Text PDFGenetic variants are vital in informing clinical phenotypes, aiding physical diagnosis, guiding genetic counseling, understanding the molecular basis of disease, and potentially stimulating drug development. Here we describe two families with an ultrarare ACVR1 gain-of-function pathogenic variant (codon 375, Arginine > Proline; ACVR1 ) responsible for a mild nonclassic fibrodysplasia ossificans progressiva (FOP) phenotype. Both families include people with the ultrarare ACVR1 variant who exhibit features of FOP while other individuals currently do not express any clinical signs of FOP.
View Article and Find Full Text PDFBackground: Considerable variability exists in the speech recognition abilities achieved by children with cochlear implants (CIs) due to varying demographic and performance variables including language abilities.
Purpose: This article examines the factors associated with speech recognition performance of school-aged children with CIs who were grouped by language ability.
Research Design: This is a single-center cross-sectional study with repeated measures for subjects across two language groups.
Little is known about FOP in Africa and few cases of nonclassic fibrodysplasia ossificans progressiva (FOP) have been reported on the continent. Here we report a three-year-old girl from Angola with a nonclassic FOP clinical presentation that is characterized by complex malformations of the toes and fingers, reduction defects of the digits, absence of nails, progressive heterotopic ossification, and a confirmed heterozygous ACVR1 variant at c.983G > A.
View Article and Find Full Text PDFFront Cell Dev Biol
December 2020
Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder in which extensive heterotopic ossification (HO) begins to form during early childhood and progresses throughout life. Although HO does not occur during embryonic development, children who carry the mutation that causes most cases of FOP characteristically exhibit malformation of their great toes at birth, indicating that the mutation acts during embryonic development to alter skeletal formation. Despite the high prevalence of the great toe malformation in the FOP population, it has received relatively little attention due to its clinically benign nature.
View Article and Find Full Text PDFThe development of joints in the mammalian skeleton depends on the precise regulation of multiple interacting signaling pathways including the bone morphogenetic protein (BMP) pathway, a key regulator of joint development, digit patterning, skeletal growth, and chondrogenesis. Mutations in the BMP receptor ACVR1 cause the rare genetic disease fibrodysplasia ossificans progressiva (FOP) in which extensive and progressive extra-skeletal bone forms in soft connective tissues after birth. These mutations, which enhance BMP-pSmad1/5 pathway activity to induce ectopic bone, also affect skeletal development.
View Article and Find Full Text PDFFibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder of extraskeletal bone formation, but could appropriately be viewed as a seminal disorder of osteochondrogenesis. Many, if not most, of the musculoskeletal features of FOP are related to dysregulated chondrogenesis including abnormal articular cartilage formation, abnormal diarthrodial joint specification, growth plate dysplasia, osteochondroma formation, heterotopic endochondral ossification (HEO), and precocious arthropathy. In FOP, causative activating mutations of Activin receptor A type I (ACVR1), a bone morphogenetic protein (BMP) type I receptor, are responsible for the osteochondrodysplasia that impacts developmental phenotypes as well as postnatal features of this illustrative disorder.
View Article and Find Full Text PDFRationale: Fibrodysplasia ossificans progressiva (FOP) is primarily a disease of progressive heterotopic ossification (HO) leading to impaired mobility throughout life. An additional diagnostic feature is a characteristic malformation of the great toes. The culpable gene for FOP,ACVR1 (activin A receptor type 1) has a clear effect on the induction of extra-skeletal bone formation.
View Article and Find Full Text PDFA 16-year-old girl with a history of nontraumatic swelling of both forearms, osteochondromas of the knees, heterotopic ossification of the neck and back, severe malformations of all digits with hypoplastic or absent nails, alopecia partialis of the scalp, and moderate cognitive impairment was seen for diagnostic evaluation. Whole exome sequencing identified an activating mutation of ACVR1 (c.983G > A; p.
View Article and Find Full Text PDFBackground: Congenital bilateral hallux valgus with associated absence or fusion of the interphalangeal joint is a classic diagnostic feature of fibrodysplasia ossificans progressiva (FOP), a human genetic disease of extra-skeletal bone formation caused in nearly all cases by a gain-of-function mutation in Activin A Receptor I/Activin-like Kinase 2 (ACVR1/ALK2), which encodes a bone morphogenetic protein (BMP) Type 1 receptor. This toe malformation prompts the suspicion of FOP even before the appearance of extra-skeletal bone. Here we report the case of a four-month-old child who was suspected of having FOP on the basis of a great toe malformation identical to that seen in children with the disease.
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