Normal echocardiographic findings in healthy pregnant women: A narrative review of the literature.

During pregnancy, significant physiological changes occur that result in cardiac remodeling and altered functional performance, though these are generally reversible postpartum. Pregnancy increases the cardiovascular system's demand, requiring substantial adaptations such as elevated cardiac output (CO), plasma volume, stroke volume (SV), and heart rate (HR), alongside a reduction in systemic vascular resistance (SVR) and mean arterial pressure. These adaptations, essential to meet the hemodynamic needs of both the mother and fetus, often differ from standard echocardiographic measurements used to evaluate cardiac function, making interpretation challenging.

Fragile X syndrome and connective tissue dysregulation.

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disabilities and autism spectrum disorders, and it is an X-linked disorder in which there is a deficiency of the fragile X mental retardation 1 protein. This protein is crucial in regulating translation of mRNAs related to dendritic maturation and cognitive development. The phenotype of FXS is characterized by neurobehavioral alterations, social deficits, communication difficulties, and findings which suggest an alteration of connective tissue, especially in the ligaments and muscles, cardiovascular system and genitourinary system.

Fragile X syndrome.

Fragile X Syndrome (FXS) is a genetic disease due to a CGG trinucleotide expansion, named full mutation (greater than 200 CGG repeats), in the fragile X mental retardation 1 gene locus Xq27.3; which leads to an hypermethylated region in the gene promoter therefore silencing it and lowering the expression levels of the fragile X mental retardation 1, a protein involved in synaptic plasticity and maturation. Individuals with FXS present with intellectual disability, autism, hyperactivity, long face, large or prominent ears and macroorchidism at puberty and thereafter.