Why do I look the way I look?

Everything you see in the mirror –from your height to your hair color to the dimple (or lack thereof) on your chin –is return into every cell of your DNA, spiraling chains of proteins found in every cell in your body. Tank of DNA as your body’s instruction manual. It tells your cells how to grow into organs, hair, teeth, fingernails, your tongue and every single other part of your body. Stretches of DNA (called genes) are like pages in that instruction manual. Genes control what you will look like, plus less obvious traits such as whether you have perfect vision or the ability to curl your tongue. 



Where did I get my genes?

While you admire your good looks in the mirror, don’t forget to thanks your parents .Genes come in pairs: one from mother and other from father. It’s the combinations of GENES that bring about –or “express” – various physical traits (in a process called heredity). Some GENES are more influential on your appearances than others. The GENES for dark hair are dominant or our GENES for RED and BLOND hair, making dark hair more common.

Do animals Have DNA?

Yes, all of them do, actually. And not just animals. Every living thing on earth – including single-celled bacteria, trees and plants- has DNA in its cells. You might expect to share many GENES with a chimpanzee or bonobo, our closest living relatives, but did you know you also shares genes with that banana the chimp is chomping??

Why do some kids look less like their parents than other kids do?

You can’t always guess a child appearance just by looking at his or her parents. The study of GENES- called genetics – is achieving breakthroughs all the times, but much about heredity remains mysterious. Combinations of GENES can affect other GENES, leading to unpredictable characteristics or features that lurk in the genetic background for several generations. Our GENES are also riddled with so called junk DNA. That doesn’t seem to express itself in any noticeable way. Environment and diet also play a large Role in shaping a person’s weight, skin tone, and other physical characteristics.


How similar Am I genetically to a CHIMPANZEES (96%-99%) ?
Humans and chimps split from a common ancestors between I3 and 16 million years ago.

How similar Am I genetically to a FRUIT FLY (60%) ?

Consider this the next time you swat that itty-bitty bug buzzing around your cantaloupe:you and that fly are related (so are you and the cantaloupe) fruit files and share many basic GENES, along with some GENES that might make you more vulnerable to cancer. Infact scientists are studying fruit files for clues to beating cancer.

How similar Am I genetically to my pet dog (82%) ?

Dogs might be “man’s best friend” , but read on for the snocking truth.

How similar Am I genetically to my pet cat (90%) ?

It turns out humans shares more genes with felines than with fido.

How similar Am I genetically to a BANANA (50%) ?

No,this doesn’t mean you are half banana. All life-forms on earth share fundamental features and functions at the cellular level.sharing half our GENES with a banana just shows that we evolved from a common ancestor more than a billions ago. 

Orthopedics Studies

Orthopedics Case Study

Neurology Case Study

Gynaecology Case Study - AMENORRHOEA

History

A 32-year-old woman complains that she has not had a period for 3 months. Four home pregnancy tests have all been negative. She started her periods at the age of 15 years and until 30 years she had a normal 27-day cycle. She had one daughter by normal delivery 2 years ago, following which she breast-fed for 6 months. After that she had normal cycles again for several months and then her periods stopped abruptly. She was using the progesterone only pill for contraception while she was breast-feeding and stopped 6 months ago as she is keen to have another child. She reports symptoms of dryness during intercourse and has experienced sweating episodes at night as well as episodes of feeling extremely hot at any time of day. There is no relevant gynaecological history. The only medical history of note is that she has been hypothyroid for 10 years and takes thyroxine 100μg per day. She does not take any alcohol, smoke or use recreational drugs.

Examination

Examination findings are unremarkable

Questions

What is the diagnosis?

What further investigations should be performed?

What are the important points in the management of this woman?

 

Answer

This woman has symptoms of amenorrhoea as well as hypo-oestrogenic vasomotor symptoms and vaginal dryness. The diagnosis is of premature menopause, confirmed by the very high gonadotrophin levels. High levels occur because the ovary is resistant to the effects of gonadotrophins, and negative feedback to the hypothalamus and pituitary causes increasing secretion to try and stimulate the ovary. Sheehan’s syndrome (pituitary necrosis after postpartum haemorrhage) would also cause amenorrhoea but would have inhibited breast-feeding and all menstruation since delivery.

Premature menopause (before the age of 40 years) occurs in 1 per cent of women and has significant physical and psychological consequences. It may be idiopathic but a familial tendency is common. In some cases it is an autoimmune condition (associated with hypothyroidism in this case). Disorders of the X chromosome can also be associated.

Effects of premature menopause

Hypo-oestrogenic effects

 - vaginal dryness

 - vasomotor symptoms (hot flushes, night sweats)

 - osteoporosis

 - increased cardiovascular risk

Psychological and social effects

 - infertility

 - feeling of inadequacy as a woman

 - feelings of premature ageing and need to take hormone-replacement therapy (HRT)

 - impact on relationships

 

Further investigations

Repeat gonadotrophin level is required to confirm the result and exclude a midcycle gonadotrophin surge or fluctuating gonadotrophins. Bone scan is necessary for baseline bone density and to help in monitoring the effects of hormone replacement. Chromosomal analysis identifies the rare cases of premature menopause due to fragile X syndrome or Turner’s syndrome mosaicism.

Management

Osteoporosis may be prevented with oestrogen replacement, with progesterone protection of the uterus. Traditional HRT preparations or the combined oral contraceptive pill are effective, the latter making women feel more ‘normal’, with a monthly withdrawal bleed and a ‘young person’s’ medication. Her options are adoption, accepting childlessness and in vitro fertilization (IVF) with donor oocytes.

Occasionally premature menopause is a fluctuating condition (resistant ovary syndrome) whereby the ovaries may function intermittently. Contraception should therefore be used.

If it would be undesirable to become pregnant.

Patient support organizations are a good source for women experiencing such an unexpected and stigmatizing diagnosis.

KEY POINTS

Premature menopause (<40 years) occurs in 1 per cent of women.

Oestrogen replacement is essential for bone and cardiovascular protection.

It may be possible to conceive with IVF using donor oocytes.