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The syndrome is diagnosed in an increasing number of children prenatally by amniocentesis and chorionic villus sampling [24] in order to obtain a chromosome karyotype, where the abnormality can be observed. It is estimated that only 15–20% of children with 47,XYY syndrome are ever diagnosed. Of these, approximately 30% are diagnosed prenatally.
The age of diagnosis varies depending on manifestations of disease prompting reason for cytogenetic testing. Many patients are diagnosed prenatally due to fetal factors (increased nuchal fold, or abnormal levels of serum ), maternal age or abnormal ultrasounds, while others will be diagnosed postnatal due to external genital malformation. [ 2 ]
The presentation of XYYY syndrome is variable and at this time not entirely clear. As all known cases were diagnosed postnatally (after birth), and the similar XYY syndrome is known to have a milder phenotype in prenatally than postnatally diagnosed cases, it is suspected that many cases of XYYY syndrome may be mild or asymptomatic.
46,XX/46,XY chimeric or mosaic is associated with a wide spectrum of different physical presentations, with cases ranging from having a completely normal male or female phenotype [7] [8] [9] to some cases having ovotesticular syndrome. Due to this variation, genetic testing is the only way to reliably make a diagnosis.
CPM occurs in one of two ways: Mitotic CPM - Mitotic non-disjunction can occur in a trophoblast cell or a non-fetal cell from the inner cell mass creating a trisomic cell line in the tissue which is destined to become the placental mesoderm.
In 2005, researchers found a connection between expressive language delay and a genetic abnormality: a duplicate set of the same genes that are missing in individuals with Williams-Beuren syndrome. Also so called XYY syndrome can often cause speech delay. [39] Twins. Being a twin increases the chance of speech and language delays.
Turner syndrome is usually not diagnosed until a delayed onset of puberty with Müllerian structures found to be in infantile stage. [4] Physical phenotypic characteristics include short stature, dysmorphic features and lymphedema at birth. [23] Comorbidities include heart defects, vision and hearing problems, diabetes, and low thyroid hormone ...
48,XXYY syndrome is a condition related to the X and Y chromosomes (the sex chromosomes). People normally have 46 chromosomes in each cell.Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics.