Purpose: Smith-Magenis syndrome (SMS), a rare, genetically linked complex developmental disorder caused by a deletion or mutation within chromosome 17p11.2, is associated with delays in speech-language development, otopathology, and hearing loss, yet previous studies lack comprehensive descriptions of hearing and communication profiles. Here,…

Angelman syndrome (AS) is a neurogenetic disorder characterized by delays including a severe expressive language delay, motor concerns, ataxia, epilepsy, sleep disturbances, gastrointestinal problems, and characteristic behaviors, including a happy demeanor, hyperactivity, and excitability. The syndrome is one of the first neurodevelopmental…

Background: Although language difficulties are one of the most distinctive characteristics of the neuropsychological profile of children with sex chromosome trisomies (SCT), the analysis of the maternal input addressed to them is a neglected topic. Aims: The present study aims to analyse the lexical, morphosyntactic, and functional features of the…

In the present study, language performance on standardized assessments (e.g., overall verbal performance, receptive and expressive vocabulary) and spontaneous language produced in play was compared between preschool-aged boys with autism spectrum disorder ([subscript n]ASD, n = 25) and boys with fragile X syndrome (FXS, n = 16). At the…

Background: Rubinstein-Taybi syndrome (RSTS) is a multiple congenital anomaly syndrome characterised by several typical somatic characteristics and by developmental disabilities with various degrees of severity. Focusing on children with RSTS, the aim of this study was to describe their psychomotor, cognitive, and socio-emotional developmental…

Background and Aims: Individuals with fragile X syndrome (FXS) characteristically struggle with language and communication throughout the life course, but there is limited research on the development of communication before 24 months. The purpose of this study is to describe the early communication of infants and toddlers with FXS using the…

Individuals with sex chromosome trisomies (SCTs) have an increased risk of language delays and impairments. However, there are only a few data relative to their language development in early childhood. The present study aimed to investigate the preverbal skills shown by a group of 8-month-old children with SCTs to assess the presence of a possible…

In order to understand how language abilities emerge in typically and atypically developing infants and toddlers, it is important to embrace complexity in development. In this paper, we describe evidence that early language development is an experience-dependent process, shaped by diverse, interconnected, interdependent developmental mechanisms,…

Chromosomal 16p11.2 deletion syndrome frequently presents with intellectual disabilities, speech delays, and autism. Here we investigated the Dolmetsch line of 16p11.2 heterozygous (+/-) mice on a range of cognitive tasks with different neuroanatomical substrates. Robust novel object recognition deficits were replicated in two cohorts of 16p11.2…

This is a naturalistic study of the development of language in Hebrew-speaking children with Williams syndrome (WS) and children with Down syndrome (DS), whose MLU extended from 1[multiplied by]0 to 4[multiplied by]4. Developmental curves over the entire span of data collection revealed minor differences between children with WS, children with DS,…

This study investigates whether distinct neurodevelopmental disorders show distinct patterns of impairments in particular grammatical abilities and the relation of those grammatical patterns to general language delays and intellectual disabilities. We studied two disorders (autism and Williams syndrome [WS]) and two distinct properties (Principle…

Phelan-McDermid syndrome (PMS) is a multiple congenital anomalies and intellectual disabilities syndrome associated with a deletion of chromosome 22 terminal band 13.3. The deletion is associated with severe intellectual disabilities, absent or delayed speech, behavior problems, and autism. The objective of this study was to provide a detailed…

Floating-Harbor syndrome is a rare congenital disorder characterized by specific facial features, short stature associated with significantly delayed bone age and language impairment. Although language delay is a cardinal manifestation of this syndrome, few reports describe the specific language difficulties of these patients, particularly the…

Guanidinoacetate methyltransferase (GAMT) deficiency is a disorder of creatine biosynthesis, characterized by early-onset learning disability and epilepsy in most affected children. Severe expressive language delay is a constant feature even in the mildest clinical phenotypes. We report the clinical, biochemical, imaging, and treatment data of two…

This article reviews research on speech and language abilities in people with cri du chat syndrome (CCS). CCS is a rare genetic disorder, with an estimated incidence between 1 in 15,000 and 1 in 50,000 births, resulting from a deletion on the short arm of chromosome 5. In general, individuals have delayed speech and language development, and some…