I found out the corresponding gene code by accident, for Yuran Race mod it's located under

~/Library/Application\ Support/Steam/SteamApps/workshop/content/*/2844129100/Bio1.4/Defs/YuranBioTitle.xml

So the official description can be found at (or wiki):

~/Library/Application\ Support/Steam/SteamApps/common/RimWorld/RimWorldMac.app/Data/Biotech/Defs/GeneDefs/

I need to use the dev tool to modify gene of my pawn, so here's the table:

import os
import xml.etree.ElementTree as ET
p = os.path.expanduser('~/Library/Application Support/Steam/SteamApps/common/RimWorld/RimWorldMac.app/Data/Biotech/Defs/GeneDefs/')
fields = 'defName label description biostatCpx biostatMet biostatArc'.split()
print('| %s |' % ' | '.join(fields))
print('|--------' * len(fields) + '|')
for f in os.listdir(p):
    root = ET.fromstring(open(p + f).read())
    for elem in root.findall('GeneDef'):
        vals = [t.text if isinstance(t:=elem.find(x), ET.Element) else '' for x in fields]
        if vals[0]:
            print('| %s |' % ' | '.join(vals))

The result is:

defName label description biostatCpx biostatMet biostatArc
Hair_BaldOnly no hair Carriers of this gene grow no hair on the head.
Hair_ShortOnly short-haired Carriers of this gene can only grow short hair.
Hair_LongOnly long-haired Carriers of this gene grow hair on the head very quickly.
Hair_Grayless grayless hair Carriers of this gene keep their natural hair color as they age.
Beard_BushyOnly only bushy beards Male carriers of this gene experience rapid beard growth and are uncomfortable cutting their beards.
Beard_NoBeardOnly beardless Carriers of this gene grow no facial hair.
Beard_Always unisex beards Carriers of this gene always have thick facial hair, even women.
Skin_InkBlack ink black skin Carriers of this gene produce a pigment that turns their skin a pale black color almost as dark as ink.
Skin_SlateGray slate gray skin Carriers of this gene produce a pigment that turns their skin slate gray.
Skin_LightGray light gray skin Carriers of this produce a light-gray pigment in their skin.
Skin_SheerWhite sheer white skin Carriers of this gene have sheer white skin, unlike natural skin tones, due to a special engineered reflective cell covering.
Skin_Blue blue skin Carriers of this gene produce a pigment that turns their skin a blue color.
Skin_Purple purple skin Carriers of this gene produce a pigment that gives their skin a purple color.
Skin_PaleRed pale red skin Carriers of this gene produce a pigment that turns their skin a moderate red color.
Skin_DeepRed deep red skin Carriers of this gene produce a deep-red pigment that gives their skin an almost bloody appearance.
Skin_PaleYellow pale yellow skin Carriers of this gene produce a pigment that turns their skin a grayish yellow color.
Skin_DeepYellow deep yellow skin Carriers of this gene produce a pigment that gives their skin a deep yellow color.
Skin_Orange orange skin Carriers of this gene produce a pigment that gives their skin an orange color.
Skin_Green green skin Carriers of this gene produce a pigment that gives their skin a green color.
Furskin furskin Carriers of this gene grow thick fur all over their body, which protects them from cold temperatures. 1 -1
Eyes_Red red eyes Carriers of this gene have deeply red-pigmented eyes.
Eyes_Gray gray eyes Carriers of this gene have pale white-gray eyes.
Brow_Heavy heavy brow Carriers of this gene have a prominent brow. 0
Tail_Furry furry tail Carriers of this gene grow a fluffy tail which partially protects them from cold temperatures. 1 -1
Tail_Smooth smooth tail Carriers of this gene grow a slender tail that can act as a dexterous fifth limb. 1 -1
FacialRidges facial ridges Carriers of this gene grow raised ridges of skin on their face. 0
MinTemp_SmallIncrease cold weakness Carriers of this gene are slightly less comfortable in cold temperatures. 1
MinTemp_SmallDecrease cold tolerant Carriers of this gene are slightly more comfortable in cold temperatures. -1
MinTemp_LargeDecrease cold super-tolerant Carriers of this gene are much more comfortable in cold temperatures. -2
MaxTemp_LargeIncrease heat super-tolerant Carriers of this gene are more comfortable in warm temperatures. -2
MaxTemp_SmallIncrease heat tolerant Carriers of this gene are slightly more comfortable in warm temperatures. -1
MaxTemp_SmallDecrease heat weakness Carriers of this gene are slightly less comfortable in warm temperatures. 1
PsychicAbility_Deaf psychically deaf Carriers of this gene are deaf to all psychic energy and influence outside their own minds. They cannot be affected by psychic influence, nor can they ever wield psychic power. 2
PsychicAbility_Dull psychically dull Carriers of this gene are less psychically-sensitive than others. 1
PsychicAbility_Enhanced psy-sensitive Carriers of this gene are more psychically-sensitive than average. -2
PsychicAbility_Extreme super psy-sensitive Carriers of this gene are much more psychically-sensitive than most. 2 -5
MoveSpeed_Slow slow runner Carriers of this gene move more slowly than normal. 3
MoveSpeed_Quick fast runner Carriers of this gene move more quickly than normal. -3
MoveSpeed_VeryQuick very fast runner Carriers of this gene move much more quickly than normal. -5
Beauty_VeryUgly very unattractive Carriers of this gene have misshapen, asymmetrical facial structures and blotchy skin. They're hard to look at. 2
Beauty_Ugly unattractive Carriers of this gene have exaggerated facial features and poor skin that are generally considered ugly. 1
Beauty_Pretty attractive Carriers of this gene have unusually symmetrical, balanced facial features and extra-clear skin which gives them a pleasing appearance. -1
Beauty_Beautiful very attractive Carriers of this gene have remarkably precise and symmetrical faces. Their features are distinctive and strong without being exaggerated, and their skin is nearly perfect. They are generally seen as beautiful. -2
Learning_Slow slow study Carriers of this gene have deficient long-term memories and don't understand new ideas quickly. They are slow at learning new skills and knowledge. 2
Learning_Fast quick study Carriers of this gene have excellent memories and grasp new ideas quickly. They learn faster than others. 2 -3
Mood_Depressive very unhappy Carriers of this gene are highly predisposed to negative emotion. They'll see the bad in every situation and have a much lower mood than others. 5
Mood_Pessimist unhappy Carriers of this gene are predisposed to pessimistic perceptions. They'll tend to interpret things negatively and have lower mood than others. 3
Mood_Optimist happy Carriers of this gene are predisposed to optimistic feelings. They'll have higher mood than others. 2 -1
Mood_Sanguine very happy Carriers of this gene are highly predisposed to optimism and not at all inclined to think negatively. They'll have much higher mood than others. 3 -2
ToxResist_Partial tox resistance Carriers of this gene are resistant to toxic buildup from any source. This includes pollution, toxic fallout, tox gas, and direct attacks with venom or injected poison. They'll gain half the amount of toxic buildup compared to others.\n\nCellular filters in the lung and skin reduce the dose of toxins entering the bloodstream. -2
ToxResist_Total tox immunity Carriers of this gene are totally immune to toxic buildup from all sources including polluted terrain, toxic fallout, tox gas, and direct attacks with venom or injected poison. They are also not bothered by acidic smog.\n\nThe carrier's biochemical pathways are modified to route around interference from nearly all known toxins. Along with enhancements to the kidneys and liver, this keeps carriers comfortable in even the most toxic of environments. 2 -4
Delicate delicate Carriers of this gene take greater injuries than others from the same damage. They have thin, brittle bones and less binding molecules in joints and flesh. 3
Robust robust Carriers of this gene take less injuries than others from the same damage. They have thickened, densified bones, nearly-solid ribcages, and strengthened binding factors in joints and flesh. -2
Pain_Reduced reduced pain Carriers of this gene feel half as much pain compared to a baseliner. Reduced neuron activity in the brain's nociception centers makes pain dull and faint. This can be advantageous sometimes, and dangerous other times. -1
Pain_Extra extra pain Carriers of this gene feel more pain than others given the same injuries. Neuron activity in the brain's nociception center is amplified, so pain feels extra-intense and fiery. This can be protective, but overall it's considered a negative and makes it hard to push through difficult situations. 2
Aggression_DeadCalm dead calm Carriers of this gene feel calm in every situation and have a very placid demeanor. They will never start social fights or have aggressive mental breaks. -1
Aggression_Aggressive aggressive Carriers of this gene are quick to anger. They are twice as likely to start social fights. When they have mental breaks, they are twice as likely to choose an aggressive kind of break. 2
Aggression_HyperAggressive hyper-aggressive Carriers of this gene are hormonally high-strung and very aggressive. They are three times as likely to start social fights. Any mental break they have will be of an aggressive type. 3
VerySleepy very sleepy Carriers of this gene get tired much faster than others. 4
Sleepy sleepy Carriers of this gene get tired somewhat faster than others. 2
LowSleep low sleep Carriers of this gene get tired less quickly than others. 2 -4
Neversleep never sleep Carriers of this gene have a unique metabolic process which allows clusters of neurons to sleep while the rest of the brain stays awake. They never need to sleep. 3 -6
MeleeDamage_Weak weak melee damage Carriers of this gene do less damage in close-quarters combat. Weak fast-twitch muscle fibers make their strikes shaky and weak. 1
MeleeDamage_Strong strong melee damage Carriers of this gene do more damage in close-quarters combat. Extra-strong fast-twitch muscle fibers make their strikes accurate and powerful. -2
UVSensitivity_Mild mild UV sensitivity Carriers of this gene have biological compounds in their skin that react painfully to UV radiation. They are unusually sensitive to sunlight. 3
UVSensitivity_Intense intense UV sensitivity Carriers of this gene have biological compounds in their skin that react dangerously to UV radiation. They are intensely sensitive to sunlight. 2 4
Libido_Low low libido Carriers of this gene are less likely to engage in lovin' with their partner.
Libido_High high libido Carriers of this gene are more likely to engage in lovin' with their partner.
FireSpew fire spew Carriers are able to spew flammable bile generated by a special organ in their neck. The bile sticks to anything in a small area and can ignite people, objects, and the ground. -2
FoamSpray foam spray Carriers grow glands in the neck that generate and store a fire-retardant foam. They can spew this foam over an area to extinguish fires. -2
LongjumpLegs longjump legs Carriers have special hemogen-powered muscle fibers in their legs which allow them to jump great distances. -2
AnimalWarcall animal warcall Carriers of this gene can perform an animal warcall, using a powerful bellow and psychic connection to call an animal to fight for them. 1 -3
Bloodfeeder bloodfeeder Carriers of this gene have small retractable fangs and an organ on the roof of the mouth which can extract hemogen from fresh warm blood. They can bite an unresisting person, suck the blood, and gain hemogen directly. -1
Coagulate coagulate Carriers of this gene have special glands on their hands and wrists, as well as a unique salivary compound that they can use to rapidly tend wounds. -1
XenogermReimplanter gene implanter Carriers of this gene can implant a copy of their xenogerm into another person through a somewhat gross-looking injector organ. Their own genetic material will then regrow very slowly. If they implant while their genes are regrowing, they will die. Germline genes will be unaffected. 3 1
PiercingSpine piercing spine Carriers grow an opening in their upper chest along with a quiver of keratin spines. Using a hemogen-powered chemical reaction, they can fire these spines at high speed at nearby targets with surprising accuracy. -1
AcidSpray acid spray Carriers grow glands in the neck that generate and store a sticky acid substance, along with acid-tolerant tissues in the mouth. They can spew this acid over an area, where it will stick to enemies and burn them over time. -2
Body_Fat fat body Carriers can have fat bodies. A person can have more than one body type gene; one body type will be chosen among those that are allowed.
Body_Thin thin body Carriers can have thin bodies. A person can have more than one body type gene; one body type will be chosen among those that are allowed.
Body_Hulk hulk body Carriers can have large bodies. A person can have more than one body type gene; one body type will be chosen among those that are allowed.
Body_Standard standard body Carriers can have average-shaped bodies. A person can have more than one body type gene; one body type will be chosen among those that are allowed.
Ears_Human human ears Carriers of this gene have regular human ears.
Ears_Pig pig ears Carriers of this gene will grow pointed pig-like ears.
Ears_Floppy floppy ears Carriers of this gene grow long, floppy hound-like ears.
Ears_Cat cat ears Carriers of this gene have cat-like ears.
Ears_Pointed pointed ears Carriers of this gene have pointed ears.
Nose_Human human nose Carriers of this gene have regular human noses.
Nose_Pig pig nose Carriers of this gene have pig-like snouts.
Jaw_Baseline human jaw Carriers of this gene have regularly-shaped jaws.
Jaw_Heavy heavy jaw Carriers of this gene have large jaws.
Head_Gaunt gaunt head Carriers of this gene have a pinched, gaunt appearance in their face and head.
Hands_Human human hands Carriers of this gene have regular human hands. 0
Hands_Pig trotter hands Carriers of this gene have hands that partially resemble pig trotters. This reduces their ability to manipulate objects. 1 1
ElongatedFingers elongated fingers Long, delicate fingers improve the carrier's manipulation capacity. This aids with many tasks, especially crafting and construction. 1 -1
Headbone_Human human headbone Carriers of this gene have regular human skulls.
Headbone_MiniHorns mini-horns Carriers of this gene grow two small horns protruding from the forehead.
Headbone_CenterHorn center-horn Carriers of this gene grow a single horn protruding from the center of the forehead.
Voice_Human human voice Carriers of this gene have regular human vocal chords.
VoicePig pig voice Carriers have a squealing voice like that of a pig.
VoiceRoar roar voice Carriers have an animal-like roaring voice.
Hemogenic hemogenic Carriers of this gene have a reserve of biological strength powered by a resource called hemogen. The resource can be gained and spent in various ways, all of which are unlocked by other genes.\n\nCarriers lose 2 hemogen per day from biological entropy. 1 1
HemogenDrain hemogen drain Carriers lose an additional 8 hemogen per day from biological entropy. 1 6
FireWeakness tinderskin Carriers have dry, thin skin which burns easily from fire, and their immune systems react very poorly to this kind of threat. Damage from fire is multiplied by 4. 2
FireTerror pyrophobia Carriers of this gene have an intense fear of fire. When fires are close, there is a chance they will have a mental breakdown at any moment. 4
PerfectImmunity perfect immunity Carriers of this gene have archite-enhanced immune systems which intelligently destroy invaders. They are totally immune to most normal illnesses. 3 1
DiseaseFree non-senescent Carriers of this gene do not go through senescence in the normal way. They never get chronic age-related diseases like cancer, bad back, cataracts, or dementia. 3 1
TotalHealing scarless Carriers of this gene have a special type of regenerator cell which can heal old wounds and chronic illnesses like bad back. 4 1
Deathrest deathrest Carriers of this gene must periodically regenerate themselves in a special coma called deathrest. Deathrest takes days, but can confer substantial bonuses. Deathrest can be accelerated and its effects enhanced by the use of a variety of special buildings and technologies.\n\nThose who put off deathresting will suffer from deathrest exhaustion. 6
Ageless ageless Carriers of this gene have archites in the bloodstream which continuously reverse the process of aging. Starting at the age of 13, carriers begin to biologically age slower. By 18, the aging process stops completely. 3 1
Deathless deathless Carriers of this gene have archites in the blood which will sustain their life processes no matter what. As long as the brain remains intact, a carrier of this gene will never die. 7 1
ArchiteMetabolism archite metabolism Carriers of this gene have special archites in their cells that facilitate and optimize metabolism. This improves overall genetic and metabolic quality. 6 6 2
WoundHealing_Slow slow wound healing Carriers of this gene heal from wounds half as fast as normal. 2
WoundHealing_Fast fast wound healing Carriers of this gene heal from wounds twice as fast as normal. -2
WoundHealing_SuperFast superfast wound healing Carriers of this gene heal from wounds four times as fast as normal. -3
Immunity_Weak weak immunity Carriers of this gene gain immunity to diseases more slowly than normal. They may die from infections that others would survive. 2
Immunity_Strong strong immunity Carriers of this gene gain immunity to diseases faster than normal. -1
Immunity_SuperStrong super immunity Carriers of this gene gain immunity to diseases considerably faster than normal. 2 -2
ToxicEnvironmentResistance_Partial partial antitoxic lungs Carriers of this gene are resistant to environmental toxins. They get less toxic buildup from tox gas, polluted terrain, and toxic fallout, but are still vulnerable to direct attacks with venom or injected poison. Additionally, they build up rot stink exposure slower. -1
ToxicEnvironmentResistance_Total total antitoxic lungs Carriers of this gene are immune to environmental toxins, but not from direct toxic attacks. They get no toxic buildup from tox gas, polluted terrain, or toxic fallout, and they are not bothered by acidic smog. They are still vulnerable to direct attacks like venom and injected poison. Additionally, they are immune to rot stink exposure. 2 -3
Sterile sterile Carriers of this gene cannot reproduce by natural means. 1
Fertile fertile Carriers of this gene have a higher chance of becoming pregnant or impregnating others.
Superclotting superclotting Carriers of this gene have extra-power coagulating factors in their blood, and will stop bleeding very quickly when wounded. -1
KindInstinct kind instinct Carriers of this gene are high in trait agreeableness and are very conscientious. They rarely insult others and will sometimes offer kind words to brighten the moods of those around them. They also never judge people by their appearance. -1
ViolenceDisabled violence disabled Carriers of this gene are emotionally and mentally incapable of engaging in violence. They are overwhelmingly resistant to and horrified by the idea of hurting another. 3
Nearsighted nearsighted Carriers of this gene have difficulty seeing at a distance. Their shooting accuracy at long ranges is reduced. 2
StrongStomach strong stomach Carriers of this gene have an extra toxin-filtering organ in their stomach and will never suffer from food poisoning even after eating rotten food. -1
DarkVision dark vision Carriers of this gene see well in low light and are unaffected by mood penalties related to darkness. They have a reflective layer behind the retina that amplifies their ability to see in the dark. -1
KillThirst kill thirst Carriers of this gene lust for the feeling of ending another's life. They will become irritated if they go for too long without killing someone in close combat. 4
FireResistant fire resistant Carriers of this gene have special fast-acting sweat glands and heat-resistant skin. They only take 25% of the normal damage from fire. The chance of them catching on fire is also drastically reduced. -2
Inbred inbred This genetic condition affects a person's fertility, immunity, and mental capacity. -2
RobustDigestion robust digestion Carriers of this gene grow a multi-fold stomach, allowing them to digest raw foods more efficiently than baseline humans. In general, they get the same nutrition from raw food as from if it is cooked. They also don't mind the taste of raw food at all. 2 -2
Instability_Mild mild cell instability Carriers of this gene need less metabolic energy to stay alive, at the cost of reduced stability in their cell-replication machinery. 2
Instability_Major major cell instability Carriers of this gene need much less metabolic energy to stay alive, at the cost of greatly-reduced stability in their cell-replication machinery. 4
PsychicBonding psychic bonding Carriers of this gene have a special neural organ that makes them psychically bond with a lover for life. As long as the lovers are together, they will be happy. If they are physically separated, they will be disturbed by the distance. If one dies, the other's mind will be badly disrupted. 1 -1
PollutionRush pollution stimulus Carriers of this gene get a chemical rush from being exposed to pollution. This makes them move faster and helps them think clearer. A similar gene is found in combat-engineered mega-insects. 1 -1
Unstoppable unstoppable Carriers of this gene are not slowed down when taking damage. 1 -2
NakedSpeed naked speed Carriers of this gene move slower while clothed, and faster while naked. 1 2