About 50% of patients undergo puberty normally, whereas the other 50% experiences no puberty, partial puberty without secondary sexual characteristics, or complete puberty with menstrual irregularities and/or early menopause (possibly as early as the teens). Medical literature reports four tetra-X pregnancies, two healthy, one with trisomy 21, one stillborn with omphalocele. In terms of internal organ systems, tetrasomy X patients may have abnormal vision, hearing, circulatory systems, kidneys, or nervous systems. Disorders of the eye include myopia, nystagmus, coloboma, microphthalmus, or optic nerve hypoplasia. In terms of hearing, patients are more prone to ear infections, sound blockage, or nerve abnormalities. Several cardiac defects have also been reported, including ventricular/atrial septal defects, atresia, hypoplastic right heart syndrome, patent ductus arteriosus, and conotruncal or valvular cardiac defects. Tetrasomy X patients also appear to be more prone to seizure activity, although there is no documented abnormalities in brain function or structure when analyzed using an EEG or MRI. Tetrasomy X is a chromosomal aneuploidy, meaning it arises from a defect in meiosis. This can occur when homologous X chromosomes fail to separate in the formation of the egg or sperm. Tetrasomy X is usually suspected based on symptoms present in the individual and is confirmed via karyotyping, which reveals the extra X chromosomes. The general prognosis for girls with tetrasomy X is relatively good. Due to the variability of symptoms, some tetrasomy X girls are able to function normally, whereas others will need medical attention throughout their lives. Traditionally, treatment for tetrasomy X has been management of the symptoms and support for learning. Most girls are placed on estrogen treatment to induce breast development, arrest longitudinal growth, and stimulate bone formation to prevent osteoporosis. Speech, occupational, and physical therapy may also be needed depending on the severity of the symptoms. In the echidna, this kind of chromosomal arrangement is normal, with genetic sex differentiated as follows:         Tasmanian Football League  The Tasmanian State League (TSL), colloquially known as the "Tasmanian Football League (TFL)" (formerly known as the "Tasmanian Australian National Football League (TANFL)" and several other short-term names) is the highest ranked Australian rules football league in Tasmania, Australia.