I am a 26 yo man and I was just diagnosed with 47,XYY "syndrome" (also known somewhat incorrectly as Jacobs syndrome or "supermale" syndrome), in quotes since it can be close to asymptomatic and usually not debilitating. Of course, it results from an extra copy of the Y chromosome and it was caused by an error in sperm development.

I have inherited several physical and mental anomalies as a consequence, some unpleasant, most just curious. The most evident is that I am very tall at ~ 205 cm (6'9''). This condition is underdiagnosed and poorly understood so as far as I understand there's a lot of controversy over which symptoms are really linked to the illness and what their incidence is. I suddenly realised I had a match with enough of them to warrant pestering my doc for a karyotype analysis, and here we are.

Proof. That's all I have. I could also provide photographic proof of any physical symptom if requested, but as I anticipated by itself each singular symptom is not particularly impressive nor a smoking gun for double Y.

Ask me anything you might want about my experience. I understand there could be questions about sexual development or sexuality and I am comfortable answering, but let's be medical so I can keep this thread sfw.

EDIT: I know it might sound really otrageous, but I will not reply to private requests to see my genitals. I know, I know, what a prude.

Comments: 604 • Responses: 70  • Date: 

ThePracticalDad985 karma

Are there any advantages? (I mean, other than being called "SuperMale")

throwawaxyy2052 karma

Yes, there's one.

desquibnt1600 karma

Just vague enough for everyone to know exactly what you're talking about

wardamnbolts621 karma

Found this on the wiki page. " Most 47,XYY males have normal sexual development and have normal fertility." So the dude is just lucky by coincidence most likely not from the extra Y which makes sense.

throwawaxyy80 karma

When they say that, they just mean you don't usually have any problem. Doesn't necessarily mean there is no effect at all. Studies do correlate 47,XYY with larger testicles, so I count it as a symptom.

WordsMort4772 karma

So with that, coupled with the lack of muscular coordination you mentioned in another comment, what's it like to get it on with a woman?

throwawaxyy254 karma

it was always very bizarre. I never expected it to be an actually demanding physical task, but to me any physical task is, from tying my shoes to pouring wine. So it took a while to get used to it. But the good thing about sex is it's a process and once I (and partners) learnt about my limitations, well, you can really find a way around them. It's not a big deal. Now, maybe it would have been different had I known it was because of something like this. I just thought I was a lanky goofy fucker and that was it

ArticArny9 karma

What are the limitations affecting your sexual acts?

throwawaxyy11 karma

it's a bit difficult for me to perform movements with grace or precision especially if my limbs are involved. It takes some effort to be careful or gentle

Infammo717 karma

Would you describe yourself as swift as a coursing river or moreso? Can you output a level of force equal to and/or double that of a great typoon? How does your strength compare to that of a raging fire?

throwawaxyy833 karma

Horny giraffe

spicydoughnut488 karma

What are the biggest challenges you faced growing up?

throwawaxyy1019 karma

The two biggest things that I can actually call hurdles would be

  • the emotional/social handicap I explained in the other reply, probably Asperger's. I feel like I was behind in all steps of development in relationships, and it honestly brought me a lot of pain that I couldn't figure out how to people. It was hard to make friends, to date, to articulate feelings or even to have them, or to place the right hierarchy of importance to events and people in my life. I've just recently talked to a shrink and started to get a handle on this mess

  • muscle incoordination: terribly annoying, always been there, dialed up to 11. Can't play sports, can't dance. I can barely get my hands to go where I want them, let alone when my legs are involved. Gym only helps marginally, it's really not a question of strength, nor training.

edit: add the scoliosis. Ow

RachInNH111 karma

When you wrote you couldn’t figure out “how to people” it broke my heart. I am sending you a hug.

throwawaxyy71 karma

Thank you very much

krankie89 karma


throwawaxyy21 karma

I will read on dyspraxia, thanks

Theboredshrimp220 karma

-Do you have more or less libido than the norm?

-Could tell us more about the mental anomalies ?


throwawaxyy376 karma

-Do you have more or less libido than the norm?

As far as I can tell, more, but with wild oscillations. I can get some weeks where I'm basically dead, but usually it is high. I couldn't tell you if that is really abnormal but I know in relationships I've always been the one wanting more.

-Could tell us more about the mental anomalies ?

I have always had great difficulty relating to people, understanding social cues and norms, and managing emotions. More when I was younger. I can only describe it as having incorrect emotional reactions in quality and quantity. It's likely I'm simply on the spectrum and I'm definitely going to get that tested more rigorously soon now that I know about this

I also suffer intensely from anxiety, which is a probable symptom. I have a handle on it now and live with it, but it really never goes away

tartare4562161 karma

Ok, I'll ask it.

How big is your junk? No homo.

throwawaxyy279 karma

It's large. Not porn, but still. But penises come in all shapes and sizes so I don't I consider this a real unmistakable symptom. My testicles, on the other hand, are very distinctly oversized, and they actually have been even since before I started to develop.

notepad2056 karma

How large exactly?

Like an actual measutment

throwawaxyy106 karma

I think I'd need an orchidometer to give you a meaningful answer, otherwise I'm just rubbing a tape measure on my nutsack and feel like an idiot

RIPelliott80 karma


Damn there’s something that can measure your balls? That’s insane I was under the impression everyone was using my ex girlfriends mouth instead

throwawaxyy70 karma

What's her accuracy?

notepad206 karma

No the dick lenfth

throwawaxyy5 karma


like a fat 8 in

Teyo1392 karma

From grape to grapefruit, where we ending up?

throwawaxyy66 karma


FinePointSharpie49 karma


throwawaxyy61 karma

Plums... between plums and peaches?

Mr_N_Thrope39 karma

How do you walk? You stack 'em? (SFW)

throwawaxyy73 karma

That's a good question. I feel a little embarrassed talking about this, but yeah I need to think about what I'm gonna wear if I have to walk a lot because they can hurt.

thetransportedman133 karma

Sexuality is still up for debate on how much of its development is genetic vs environmental. On a scale of 1-10 with 1 being only interested in same sex relations vs a 10 which is only interested in opposite relations, where do you feel you best fall?

throwawaxyy147 karma


thetransportedman52 karma

Same dude same haha. Thanks for doing this ama it was interesting coming from a genetics major

throwawaxyy39 karma

very smooth

hiddencountry50 karma

So have you had intimate relations with men and women? Which do you find it easier to be with? You said elsewhere you tend to see other men as threats, does that carry into the bedroom?

Thanks for doing this BTW. These kinds of things are perfect for AMA. I've always been fascinated by chromosomal differences.

throwawaxyy122 karma

I have. I find myself more comfortable with women - I feel like there's more to discover, so to speak. It's a bit colder and transactional with men. I doubt this has anything to do with my dna.

The kind of men I tend to perceive as threats are not the same kind of men I would like to go to bed with.

hiddencountry28 karma

Thank you for sharing! Though that makes me wonder, do you prefer more effeminate or masculine men as a partner? Or does that trait have nothing to do with the types you find attractive versus threatening?

throwawaxyy79 karma

I like more feminine men usually. Idk, sometimes it's the opposite. You can't possibly expect me to explain this logically

geekgiant131 karma

This is fascinating. I’ve been staring at my pinkies all morning wondering how much they’re curved. I am now wondering if I have this as well. I always assumed I was just a socially awkward, way too tall guy but the batch of symptoms sounds like it could be a fit…

I’m 6’8 and nobody in my immediate family is anywhere near that tall… thank you for sharing this. Did you come across this or were you seeking a different diagnosis?

Edit: some kind person gave me a silver in recognition for being able to reach the top shelf. Thank you!

throwawaxyy73 karma

I came across it and it just clicked. Look into it. There's a lot of misinformation, just dig through it and see how it fits you, talk to your physician.

bearable_lightness110 karma

Noninvasive prenatal aneuploidy screening has been widely adopted and is increasing used to screen for xyy syndrome. As someone with this aneuploidy, do you have any opinions regarding aneuploidy screening?

throwawaxyy105 karma

Yes. They should do it more, and more cheaply. XYY is the only aneuploidy that doesn't lead to a horrible quality of life. I would say XXY is next in a scale of severity and it's already something that I consider devastating. It might be a strong opinion but I think it's an act of cruelty to let someone live with trisomy 21 in a world where you can know in advance.

plabo7726 karma

XYY is the only aneuploidy that doesn't lead to a horrible quality of life.

XXX is another variation that I’d say is similar to XYY in terms of potential challenges.

throwawaxyy38 karma

Oh you're right, I forgot about that. I would say XXX is pretty much on the same level as XYY

pimpmyegg104 karma

We were told in class that people with Jacob's syndrome have a "criminal bent of mind". Is that true?

throwawaxyy286 karma

I don't recognize this in myself. I wasn't a cruel, violent, or disobedient kid. I was more asocial than antisocial.

Afaik this could be a byproduct of statistically biased research on XYY in the 60s and 70s. I don't know though.

HopelessHamsta98 karma

How'd you feel when you found out?

throwawaxyy267 karma

Very excited! And very weird. It gives a unified explanation for a lot of oddities and pains that I've lived with forever all at the same time. It's just good news

Distaplia96 karma

So how would meiosis work? your sperm will some have X, some Y, some YY, some XY? what are the odds your offspring will also have trisomy?

throwawaxyy149 karma

I can't figure this out. Info is unclear. I might be infertile, or less fertile. If I'm fertile, I think most of my sperm will be normal and about 50/50 X or Y, and it's not clear whether I have an increased chance of producing YY sperm compared to a healthy male. I need to get tested and/or talk to a specialist.

redheadmommyMFP91 karma

Are you more aggressive than the average male ?

throwawaxyy233 karma

More defensive. I'm not very extroverted and not prone to aggression at all but I tend to be very territorial, I don't like new people and I tend by instinct to see other men as threats. At least I notice this much more in myself than others. I guess that's what you get when you mix high testosterone and a few drop of the 'tism.

Actually I'm not really medically sure about high T, but I often do feel a lot that way.

WordsMort47133 karma

Reading some of your answers make me think that a lot of the "symptoms" of your condition could actually just be down to normal inherited physical traits and mental traits brought about throughout your upbringing- that is to say, socially acquired traits, I.e. nature vs. nurture.

throwawaxyy23 karma

may be

kittypawprints4me52 karma

What are some of the ailments that you had gone through with the extra Y chromosome, and is there a way this can be overcome, even with so little information?

throwawaxyy105 karma

Just to talk about something that I haven't mentioned yet, it has caused me to have very low muscle tone in the arms and legs. It's in fact one of the most jarring things about my body. If I'd known about this, I could have done some more specific exercise to compensate, which I've now started. I also tend to accumulate fat much much more in the central part of my body, so I have a permanent beer belly... even when I'm skeleton-thin anywhere else.

There's not a lot to overcome tbh, it's just a bunch of sprinkled quirks and you just get a few random ones from the bag. The information is very limited because it can just not hurt you or hurt you too little and it manifests apparently very differently in every case. I don't think there is one single symptom that's a given. I don't see myself as sick or really much inconvenienced. The Y chromosome is really nothing much.

adeiner40 karma

When people are like “There is only XX or XY” do you say “Well actuallllllly”? I ask because I would do that all the time.

throwawaxyy38 karma

Do people say that tho?

adeiner25 karma


throwawaxyy86 karma

Well actuallllllllly....

Matelot6733 karma

Are you struck by the irony that the condition that makes you well qualified to play basketball also denies you the muscle co-ordination to actually play basketball?

throwawaxyy109 karma

I'm also struck by an intense disinterest in basketball, so it's ok

zork82433 karma

bestemmiamo insieme?

throwawaxyy40 karma

Dio cane

IceyEnder20 karma


throwawaxyy42 karma

no per favore, un handicap alla volta

EpiceEmilie30 karma

As someone with Swyer Syndrome (46 XY "female", also called XY gonadal dysgenesis), do you consider yourself intersex, or to have a difference of sex development? I can see the argument both ways--clearly you haven't experienced typical sex development, but at the same time, the differences seem to be that you're "more" male, so intersex ("between the two sexes") wouldn't really fit. (Although some people have said that the word intersex isn't a good name for the community for that reason.)

throwawaxyy29 karma

oh, that's actually very interesting. You should do an ama, I would love to hear more about that

Tbh I feel just male. Mostly. I guess if you wanted me to rate myself from 0 female to 10 male I would say 11 or 12. But really, the kind of issues that people the word intersex was created for face, I just don't have them. I am a normal healthy male from the point of view of sexual development. Maybe my hormones are a bit crazy.

Anva9928 karma

Besides the emotional conditions, do you present any intellectual anomalies?

throwawaxyy79 karma

No. I haven't been tested in that sense so far, and I will definitely get around that as soon as possible, but my cognitive abilities seem to be do doing great. I was a smart kid, I did good in school and I now have a career in science. I also never suffered from things like dyslexia, learning delays or anything of the sort. I did and still do have legendarily bad handwriting and I think I almost drove a few kindergarten teachers to the brink of suicide, but in retrospective that is probably just a consequence of muscle incoordination.

XVepic25 karma

How does this affect your relationships?

throwawaxyy67 karma

Romantic relationships? Severely. As a teen I barely even understood what they meant. I knew I wanted sex and eventually I figured out how to get it but it took a lot more time and an awful lot of pain before I could establish an actual healthy relationship with a partner. Now I think I'm mostly ok

Friendships were easier I guess but still hard. They still are. That might be normal for my generation though

jakolissmurito17 karma

My cousin was identified with an extra Y as well when he was very young. He use to be quite aggressive and always the same size as his older brother. He has chilled out A LOT as he's grown into adulthood, and he's incredibly tall. Do you find yourself to be more aggressive than others? They say that can be a symptom.

throwawaxyy14 karma

check my other answer on aggressiveness

phyfts16 karma

Do you have a crazy deep voice?

throwawaxyy16 karma

Very deep

RoboPsycho13 karma

These might be the stupidest questions you get but as you got taller did you start running into the tops of doorways? Also, are slam dunks just an arm reach away for you?

throwawaxyy14 karma

yes and yes

Randall17213 karma

are your two y chromosomes clones of each other?

throwawaxyy30 karma

I think they should be, up to the pseudoautosomal regions, but don't take my word for it, I'm not a doctor

Noilol212 karma

Are you able to have kids?

throwawaxyy16 karma

I don't know yet

dunderthebarbarian10 karma

Did you start shaving earlier than your peers?

throwawaxyy33 karma

No, later. Overall secondary development hit later but it hit hard. Full beard now

LikelyAFox9 karma

What physical traits are different as a result?

throwawaxyy40 karma

  • significantly taller than my parents
  • lateral scoliosis
  • low muscle tone on limbs
  • accumulate fat towards center of body
  • large testicles
  • a tiny bit of clinodactyly, not much but my parents don't have it

Red-71347 karma

I guess this is more of a general genetics question but, chromosomes are part of nuclei which are part of cells, right? So when someone says they have something like extra, missing, doubled, etc. chromosomes, is it, like, for every cell in their body? Is there some master cell that others are copied off of or something?

throwawaxyy12 karma

All cells. They all carry a copy of the recipe

khaleesi20186 karma

Are you going to avoid having children so you don't pass down these genetic issues? Are your parents related or from the same community?

throwawaxyy22 karma

I don't want to have children.

Know that this disease is caused by a problem in my dad's sperm production, it's not inherited and cannot be a consequence of inbreeding. In fact, it doesn't really involve my mom at all

OwO_QwQ4 karma

Do you know any reason why you're so tall?

throwawaxyy2 karma

Yes... my parents are already tall, the extra Y gives it a boost

limonty4 karma

  • What was it like growing up as a teenager with this condition?
  • When did you realise there was something different about you?

throwawaxyy17 karma

What was it like growing up as a teenager with this condition?

Pain pain just pain. Teens was a terrible time. I really felt like there was no hope of me ever relating or connecting at all to humanity and my thoughts from that time seem like a kind of fever dream in which I was actually an alien parroting a person. I'm still in the process of untangling whatever went wrong then. Not sure if this is really exceptional. But I am sure the Y had a big part in it.

When did you realise there was something different about you?

I have always been different. I have never doubted this

MGS1234V4 karma

Other than exceptional height and the question a lot of people are wondering but aren’t asking outright regarding your... physical attributes. how does your arm span correlate to your height? (typically people are around a similar height to their wingspan) I’m curious also if the size of your hands and fingers are drastically larger proportionally? One of my taller friends, not much shorter than you actually, was not allowed to swim or do extended cardio for risk of his heart having problems. Have you experienced any limitations like this?

(Posted again with question mark as punctuation was forgotten)

throwawaxyy6 karma

I think my arms are proportionate to my height. Do you need some measurements?

My hands are very big, and fingers long, proportionally to my height, but they're not any thicker, so I got these very skeletric hands. Otherwise they look normal.

I don't have any cardiac issues as far as I know. I'm getting tested for those tomorrow, since I have a family history

Ott6213 karma

Has being diagnosed changed anything? I'm 18" taller than most of the males in my family.

throwawaxyy24 karma

It let me do a sick AMA so

ISuckAtChoosingNicks3 karma

Fellow Italian here. Did your region (ASL) pay for testing? What about any physio/treatment? Is the ASL giving you and your family any kind of support?

If they did, what was the waiting time? If not, care to share the costs of testing alone?

Also, I'd be surprised if your family doctor would know what this syndrome is...

throwawaxyy7 karma

Family docs know about it. They just are very difficult to convince there is a chance and/or that it matters. They are quite misinformed and I noticed there's a lot of confusion with XXY. I went through multiple of them and multiple tries and one finally caved in and let me have it with the ASL

Waiting time was about a month. I only paid "il ticket" of course

There is no support or further therapy. There's no real syndrome to speak of, it is not more than the sum of its symptoms. I can talk privately to my therapist about it, and that's it

Ms--Keisha2 karma

So basically Jacob's syndrome is "less noticeable" so to speak compared to other genetical aberrations such as Kleinfelter and Turner syndromes, do you have any information about why ? I mean an extra X chromosome is a total catastrophe, however an extra Y seems to have very little impact I assume, since you haven't found out until now.

throwawaxyy5 karma

chrY is both small and has lower information density than the other chromosomes. So it carries very little information overall. That's why duplication is less severe, roughly. There is an evolutionary advantage to shrinking chrY, since it is most susceptible to mutations, and it will eventually disappear completely

GorillaBunz952 karma


throwawaxyy47 karma

my dad's nuts miscounted

chrrmin2 karma

Are you fertile?

throwawaxyy6 karma

I don't know yet

TurboEntabulator2 karma

How is your strength like? And also did you have a huge appetite as a baby or toddler? Asking because it's related to parental gene silencing and you must be way into the paternal spectrum.

throwawaxyy4 karma

Considering weak musculature in arms, I guess I'm pretty strong, stronger than I can coordinate at least. On the appetite, idk about as a baby, I was very hungry as a child and I would eat a lot. Except instead of getting fat I would just get longer

KyMurrr2 karma

At 6'9", you would have innate advantages in (certain) sports, eg. basketball,volleyball, but I've also seen a lack of coordination in lots of people who played sports purely because of height. What has your relationship with sports/physical activity been like?

throwawaxyy10 karma

horrible, I don't know what to tell you. I could put no effort or all of it, it just wouldn't work. I couldn't bounce a basketball, I couldn't hit a soccer ball, I can't even play decent ping pong.

I liked when I finally started just going to the gym, doing cardio & lifting. I understood I really had the strength and enjoy physical activity, I just can't manage to do any movement that requires any decent degree of precision

thewhitestuff3 karma

Are you able to enjoy video games?

throwawaxyy4 karma

Yes, I would say I am

Sadistical1 karma

Have you had your blood work done to test your testosterone levels?

throwawaxyy3 karma

No. I had no reason to. I might probably soon. I don't expect any weirdness though

nickjayr1 karma

quindi c'hi il cazzo o la fica?

throwawaxyy1 karma

che ti cambia, comunque non te lo do

Melkor4041 karma

What do you do for a living?

throwawaxyy10 karma

I'm a scientific researcher

el___diablo1 karma

Given (assumingly) higher than average testosterone levels, are you balding prematurely ?

throwawaxyy8 karma

I'm not balding, also the link between testosterone levels and MPB is a myth as far as I know

supercharged07090 karma

Why aren’t you in the NBA?

throwawaxyy10 karma

Because I have extremely low coordination. I was forced into basketball but I was really bad at it