Did you know that genes control the age that girls have their first period?

A huge study was conducted by 166 institutions from around the world that analysed the genome/DNA sequences of over 180,000 women.

They identified 106 regions of the genome (loci) that affect the timing of puberty/first period in girls.

This includes several genes that regulate the production of hormones (e.g. oestrogen) and body weight.

This makes sense, because it is well known that hormones and body size strongly influence the timing of puberty. It emphasises the complex interplay between genes and environment (nature v’s nurture).

It might be possible in the future to sequence these 106 regions to predict when girls will have their first period. Would this be useful?

 

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Background

Virtually all of aspects of our bodies are controlled by a mixture of genes and environment (i.e. nature v’s nurture).

Girls begin puberty and get their first period (menarche) between 10-15 years of age (average 12-13).

Do genes influence the timing of the first period in girls?

Materials and Methods

A large collaboration involving scientists at 166 institutions from around the world analysed the genomes of 182,416 women of European descent (i.e. Caucasian) and correlated specific genes and regions of the genome with the onset of puberty.

Results

This huge study identified 106 genomic loci that are associated with the onset of menarche/puberty in girls.

That is, specific sequences/differences in the DNA at 106 regions of the genome that affect the timing of the first period.

These regions can be inside genes, near genes or in between genes.

Usually, they affect the expression of a gene or the activity/function of the protein it produces.

Each of these DNA sequences/loci has only a weak affect on period timing, however when several are combined, they have a stronger affect.

29 of the loci/genes affect the production of hormones (e.g. oestrogen), 9 affect body weight and 3 affect height. This makes sense, because it is well known that body size strongly influences the timing of puberty.

Discussion

It might be possible in the future to sequence these 106 regions to predict when girls will have their first period (approximate timing).

While this study focuses on the genetic influence on puberty/period timing, there are clearly also environmental factors that contribute.

Interestingly, several genes associated with body size were identified in this study. Size/weight is also strongly affected by diet and lifestyle, thus emphasising the complex interplay between genes and environment.

Article

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche

Perry et al., 2014 Nature 514:92-7

Keywords

Gene, genetic, genome, DNA, sequencing, loci, locus, GWAS, puberty, period, menarche, adolescence, development, hormone, oestrogen, weight, body, nature, nurture

Subject

Science, Biology, Genetics, SC4-14LW, ACSSU150, SC5-15LW, ACSSU184