XXXX

XXXX may refer to:

Music

See also

48, XXXX

XXXX syndrome (also called tetrasomy X, quadruple X, or 48, XXXX) is a rare chromosomal disorder caused by the presence of four X chromosomes instead of two X chromosomes. This condition occurs only in females, as there are no Y chromosomes present. Tetrasomy X was first described in 1961, and since then approximately 100 cases have been reported worldwide. Approximately 60 females have been described in medical literature with this condition.

Causes and diagnosis

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.

Symptoms

Symptoms of tetrasomy X are highly variable, ranging from relatively mild to severe. Symptoms are often similar to those of trisomy X. Physically, tetrasomy X patients tend to have distinctive facial features such as epicanthal folds, flat nasal bridges, upslanting palpebral fissures, midface hypoplasia, small mouths, cleft or high arched palates, delayed or absent teeth, or enamel defects. The majority have also been reported as being longer and taller. Many also show joint and muscle tone abnormalities, including hypotonia and joint looseness in the hips. Skeletal problems may also be present, including abnormal curvatures of the spine. An informal study conducted by Tetrasomy & Pentasomy X Syndrome Information and Support found that 10% of girls had joint laxity in the hips and 20% had joint limitations in a sample size of 20 tetrasomy and pentasomy patients.

Speaking clock

A speaking clock or talking clock is a live or recorded human voice service, usually accessed by telephone, that gives the correct time. The first telephone speaking clock service was introduced in France, in association with the Paris Observatory, on 14 February 1933.

The format of the service is similar to that of radio time signal services. At set intervals (e.g. ten seconds) a voice announces (for example) "At the third stroke, the time will be twelve forty-six and ten seconds...", with three beeps following. Some countries have sponsored time announcements and include the sponsor's name in the message.

ASEAN

In 1995, the ASEAN has set up nine speaking clocks.