Medical Suffix

-somy

chromosome bodies (copies of one chromosome)

From Greek soma, body, through chromosome, with the noun ending -y

Meaning

What does -somy mean?

-somy is a suffix meaning chromosome bodies (copies of one chromosome). It comes from Greek soma, body, through chromosome, with the noun ending -y.

The number prefix gives the count of one chromosome; cells normally carry two of each, so trisomy is one too many and monosomy one too few.

In real words

trisomy
1. Prefixtri-three
2. Suffix-somychromosome bodies (copies of one chromosome)
having three copies of a particular chromosome instead of the usual two, as in trisomy 21 (Down syndrome)
monosomy
1. Prefixmono-one, single
2. Suffix-somychromosome bodies (copies of one chromosome)
having only one chromosome of a pair instead of the usual two, as in Turner syndrome
disomy
1. Prefixdi-two, double
2. Suffix-somychromosome bodies (copies of one chromosome)
having two copies of a chromosome, the normal state in body cells; in uniparental disomy both come from one parent
tetrasomy
1. Prefixtetra-four
2. Suffix-somychromosome bodies (copies of one chromosome)
having four copies of a chromosome, or part of one, instead of the usual two, as in tetrasomy 18p
nullisomy
1. Prefixnulli-none
2. Suffix-somychromosome bodies (copies of one chromosome)
the loss of both chromosomes of a pair, so a cell has no copy of that chromosome at all

Sources

Written for biofideX in plain words, after checking these references:

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Practice it

-somy is one of 15 parts in this lesson. Learn them together, then take real words apart.