Named Disorders Flashcards
Friederich Ataxia
(AR) GAA repeats on Chr9 –> frataxin mutation; defective Fe binding protein in mitochondria. This damages dorsal columns (proprioception and vibration sense) as well as spinocerebellar tracts (ataxia, frequent falling). Also see kyphoscoliosis and pes cavus; risk of death from HCM; presents in adolescence (ages 5-15).
Charcot-Marie-Tooth disease
(AD) Progressive hereditary neurodegenerative disorders due to defective production of the structure and function proteins of the peripheral nerves/myelin sheath. Presents as sensory and motor loss, as well as kyphoscoliosis and pes cavus, around age 30-40.
Metachromatic Leukodystrophy
(AR) Lysosomal storage disorder due to arylsulfatase A deficiency and cerebroside sulfate accumulates, which impairs myelin sheath production (“leuko”- white dystrophy).
Get central and peripheral demyelination with ataxia around age 9-12mo, dementia, developmental delay, muscle weakness, atrophy, MRI showing demyelination.
Isolated Atrial Amyloidosis (IAA)
form of senile amyloidosis (associated with aging) where ANP is misfolded and deposited in the cardiac atria; increases the risk of afib
Actinic keratosis
Premalignant skin lesions that are rough with sandpaper like texture, “felt more than seen”, and start out as small/flat then become elevated and maybe even form horns (hyperkeratosis).
Caused by UV damage, therefore seen in people who worked outside a long time. Can progress to SCC (
Acyl-CoA Dehydrogenase deficiency
The most common deficiency resulting in impaired FA oxidation; the missing enzyme is the one that starts FA oxidation (once the acyl-CoA has been transported into the mitochondrion by carnitine). Clinical = fasting child with vomiting and lethargy, maybe a seizure, and hypoglycemia and NO KETONES (no acetoacetate - hypoketotic hypoglycemia).
Differentiate from GSD because there will be no ketones here.
Differentiate from primary carnitine deficiency because that will also have muscle weakness, cardiomyopathy, and elevated TGs in addition to hypoketotic hypoglycemia.
CGD
lack of NADPH oxidase means impaired NT respiratory burst and thus inc vulnerability to catalase positive bugs -
Especially Serratia, S. aureus, Burkholderia cepacia, Aspergillus, and Nocardia
Homocystinuria
Methionine cycle = Met –> SAM –> SAH –> Homocysteine; Hom –> Met, OR Hom –> Cystathione –> Cysteine
If you can’t convert Homo–> cysteine (MC 2/2 deficiency of cystathione synthase) then homocysteine accum, which makes for a hypercoagulable state, can cause acute coronary syndrome (like 12yo with angina, or CVA), can also result in ectopia lentis, ID, and long slender fingers.
This would make cysteine an essential aa for these people because they can’t make it from homocysteine. Can also supplement B6 because even when the enzyme is deficient, 50% of patients respond to supplemental pyridoxine. Should also reduce dietary methionine.
Hunter’s syndrome
deficiency of iduronate sulfatase; heparan sulfate and dermatan sulfate accumulate; similar to Hurler’s (gargolyism) except - no corneal clouding, and very aggressive
Hurler’s syndrome
deficiency of alpha-L-iuduronidase; heparan sulfate and dermatan sulfate accumulate; developmental delay, loss of milestones (develop normally for a while, then they regress), gargoylism = dwarfism, distinct facial features (frontal bossing, hypertelorism, widened nasal bridge, gapped teeth, gingival hyperplasia, and thickened tongue), cloudy corneas, HSM, airway obstruction (from thickened tongue, leads to death)
Hyperplastic arteriolosclerosis
when a patient has persistent diastolic HTN (>130), the arterioles get onion-like concentric thickening of the walls; this can lead to sustained HTN, kidney damage (oliguria), increased RAAS activity (vicious cycle), and potentially cranial sx like Has, papilledema, HTNive encephalopathy, and retinal hemorrhage/exudate
Kallman syndrome
delayed puberty + anosmia
2/2 defective migration of GnRH cells into hypothalamus, so there’s no secretion of GnRH from hypothalamus
Klinefelter syndrome
47,XXY male - primary hypogonadism, tall, gynecomastia, learning/social difficulties; dec. testosterone from damaged Leydig cells, inc. FSH/LH (no feedback; sclerosed seminiferous tubules), and inc. estradiol
Clinical hallmark is the hypogonadism - small firm testes; lack of 2ndary sex development - despite being tall
Krabbe’s Disease
deficiency of galactocerebrosidase; galactocerebide accumulates; CNS symptoms like delayed development, optic atrophy (blindness), Globoid cells (multi-nuc MPs); “4mo old with seizures, irritability, vomiting, developmental delay, inability to track(blind)…”; differentiate from Fabry’s by optic atrophy
Marfan vs. Ehlers-Danlos: mutation and clinical picture
Marfan = mutated fibrillin, all elastin all the time; person is really tall with long limbs, sunken chest; but doesn’t affect cartilage like joints
EDS = defective collagen synthesis (often lysyl hydroxylase or procollagen peptidase) to where the person has hypermobile joints, stretchy skin, and fragile tissue vulnerable to bruising
MEN1, MEN2a, MEN2b
MEN 1: pituitary, parathyroid, pancreas
MEN 2A: parathyroid, pheo’s; medullary thyroid
MEN 2B: oral/GI neuroma, pheo’s; medullary thyroid
Necrolytic migratory erythema
an elevated painful and pruritic rash affecting the face, groin, and extremities, the papules/plaques coalesce to form large lesions with bronze indurations; features in glucagonoma, which will also see high glucagon and which may present as new onset DM, +/- anemia of chronic disease
Niemann-Pick Disease
deficiency of sphingomyelinase; sphingomyelin accumulates; tetrad of neuro probs/neurodegeneration, HSM, foam cells (fatty accumulation of sphingomyelin in MPs), cherry red macula
Ornithine Transcarbamylase deficiency
Urea cycle: carbamoyl phosphate + ornithine –> citrulline
Deficiency = accum. carbamoyl phosphate, gets pushed into the pyrimidine synthesis pathway but then gets stuck at orotic acid
Findings: orotic acidemia/aciduria and hyperammonemia (a metabolic emergency - manifests as AMS/unresponsive and tachypnea); triggered by illness or excessive protein intake
*Differentiate from orotic aciduria alone: no megaloblastic anemia in OTC deficiency
Primary carnitine deficiency
without sufficient carnitine (mitochondrial membrane transport protein for FAs), FA can’t be transported into the mitochondria; they won’t be oxidized and no acetyl-CoA will be produced for either TCA or ketone bodies
Sarcoidosis
histo: non-caseating granulomas with epithelioid cells; CXR = bilateral hilar lymphadenopathy; typically a young black woman with non-specific sx like fever/malaise/wt loss; +/- skin involvement ranging from macules to painful shin nodules (erythema nodosum)
Small Cell Lung Cancer
neoplasm of primitive cells from basal layer of bronchial epithelium; can have varying degrees of neuroendocrine differentiation, as such they may stain for chromogranin/synaptophysin/NCAM-1 (aka CD56)/neuron-specific enolase, and/or they may express neurofilaments and contain secretory granules; look like LCs but typically larger, arrange in sheets or clusters
This is the cancer associated with all the syndromes: Cushing’s, PTHrP, SIADH, Eaton-Lambert
Tay-Sachs Disease
deficiency of hexosaminidase A (Tay-Six dz); GM2 ganglioside accumulates; neurological problems (CNS/peripheral), cherry red macula, NO HSM everrrrrr, onion skin lysosomes
Lynch syndrome - associated cancers
colorectal; endometrial; ovarian
–> from MSH mutation
CREST Syndrome
A type of limited scleroderma (limited meaning it doesn’t include viscera)
Anti-centromere antibodies are specific for limited scleroderma whereas anti-topo I are specific for diffuse scleroderma (aka systemic sclerosis)
C = calcinosis R = Raynaud's E = Esophageal dysmotility (like GERD or dysphagia) S = sclerodactyly (begins as non-pitting edema, then becomes thickened, ulcerated skin of hands/feet) T = telangiectasias
Androgenetic alopecia
aka male-pattern baldness
these people have higher levels of 5-alpha-reductase (turns testosterone into DHT) and a higher quantity of androgen receptors.
Finasteride (a 5-a-reductase inhibitor) will reverse androgenetic alopecia.
Turner syndrome
46,X
Loss of paternal X chromosome
Results in webbed neck/cystic hygromas, broad chest with wide nipples, streak/atrophic ovaries, short stature, horseshoe kidney, bicuspid aortic valve, coarctation of the aorta (diminished LE pulses), low set ears, low hairline, lymphedema (swelling of bilateral extremities), and overall short stature
Congenital torticollis
A contracture of the SCM caused by fetal malpositioning in utero, or traumatic delivery (breech).
This causes injury and fibrosis to the SCM, resulting in a fetal head position that is away from the side of injury.
Typically presents clinically by 2-4wks of age.
Triad of Wiskott Aldrich syndrome (and the rest of the disease)
Triad = thrombocytopenia, recurrent infections, eczema
Disease is an X-linked deficiency of both B and T cells
Tx is bone marrow transplant
WASP = the defective protein, which results in T cells not being able to polarize and therefore can’t make the immunologic synapse, can’t activate B cells; also plays role in the small platelets (removed by the spleen hence thrombocytopenia)
Alkaptonuria
AR deficiency of homogentisic acid dioxygenase; get accumulation of homogentisic acid (on its way to fumarate for TCA cycle). Relatively benign in childhood, then severe arthritis in adult life with pigment deposition in cartilage (blue-back spots in sclera and ear); the deposits are also in joints which causes ankylosis, restricted movement, and pain
+pee that turns black overnight
Hirschsprung’s disease
Failure of neural crest cells to migrate down to form the submucosal (Meissner’s) and myenteric (Auerbach) plexus; always involves the rectum because that would be the farthest sites to migrate to.
Dx with submucosal biopsy of the narrowed portion of the bowel (because the dilated part proximal to that is where everything is getting stuck, that’s why it’s big).
Lead poisoning
Child or someone who works in industry -
abdominal pain, weakness, constipation, and in severe cases neuro sx (causing HA, cognitive sx, peripheral neuropathy)
Blood smear: basophilic stippling on background of hypochromic, microcytic anemia
vs. Acute porphyria - episodes of abdominal pain without tenderness, and no anemia
Arginase deficiency
In urea cycle*
Normally: converts Arginine + H2O –> Ornithine + Urea
Without it: build up of Arginine in blood, spastic diplegia, and growth delay (“3yo boy with progressive bilateral leg stiffness and abnormal involuntary movements with delayed cognitive development”)
Differentiator is nearly no hyperammonemia at all
*The only urea cycle enzyme deficiency that is XLR
Fanconi anemia
Inherited disorder of bone marrow causing aplastic anemia.
The patient will also be short and thumbs are absent.
Increased risk of malignancy like MDS and AML.
Polyarteritis nodosa
medium-vessel vasculitis
- usually idiopathic; associated with HbsAg
- renal, skeletal, neuro, and visceral (GI) vessels (NOT lung); episodes of system symptoms due to ischemia
- string of pearls on imaging from: transmural inflammation of vessel wall with fibrinoid/eosinophilic necrosis
- immune complex mediated, especially when associated with HepBsAg (30% of cases)
Leser-Trelat
the acute eruption of multiple seborrheic keratoses that are associated with underlying internal malignancy
Myotonic muscular dystrophy
- 2nd MC inherited muscle disorder (AD), behind DMD
- caused by CTG repeats
- will always see myotonia (slow relaxation) and cataracts; frontal balding and gonadal atrophy are also common
Essential Fructosuria vs. Aldolase B deficiency
Essential Fructosuria is benign (AR) and fructose will simply be excreted in the urine.
Aldolase B deficiency is bad and presents as soon as fruit juice is introduced into the diet; infants will get jaundice, hepatomegaly, and failure to thrive.
Rett Syndrome
- hypotonia and hand ringing
- loss of developmental milestones around age 5-18mo as well as deceleration of head growth (early sign)
- normally in girls
- most cases are due to de novo mutation in X linked gene
Wilson Disease
mutation in ATP-B7 Cu transport protein in the Golgi
- will see Cu overflowing from HCs because it can’t be excreted; will instead be deposited in tissues like the brain, cornea - therefore hepatic, neuro/psych, and Kayser-Fleischer rings are clinical findings
- lab findings include increased Cu in liver biopsy and in urine, as well as decreased Ceruloplasmin (serum Cu transport)
- treat with D-Penicillamine
Minimal change disease
- a protein loss in the kidneys defined by loss of negative charge selectivity in the GBM; will see Albumin (and potentially other proteins like IgG or B2-microglobulin) in the urine
- this type of nephropathy is a selective nephropathy
Guillan-Barre
- antibodies against myelin; so you get segmental demyelination and endoneural inflammatory infiltrate (on LM will see LC/MPs)
- most often following URI, esp. Campylobacter jejuni
Tuberous sclerosis
brain tubers, subependymal hamartomas, ash-leaf skin patches, renal angiomyolipoma, cardiac rhabdomyoma, facial angiofibroma
Multiple sclerosis
- neuro issues separated by time and space, due to demyelination with relative sparing of the axons by autoantibodies
- IgG oligoclonal bands in CSF, sclerotic plaques (astrocytosis/glial scarring/inflammation) on MRI, as well as lipid-laden MPs from myelin clean-up
- Intranucleuar opthalmoplegia (INO) is a sx caused by demyelination of the MLF
Familial Hypocalciuric Hypercalcemia
- mutated CaSR (a GPCR) that can’t tell if you have enough Ca; so PTH is high, Ca in blood is high, and Ca in urine is low
- benign, AD disorder
- mutated CaSR found in kidneys and parathyroid gland
Major Depressive Disorder
A major depression (all day consecutively) lasting longer than 2 weeks
Without mania or hypomania because then that would be bipolar; must rule out bipolar and substance issues.
Hashimoto thyroiditis
The MCC of hypothyroidism in the US
- first inflammatory infiltrate and destruction of the thyroid
- then high TSH because it’s trying to get it produced
- thyroid doesn’t work so T4 is low
- T3 is normal though, until late-stage
Achalasia
an esophageal dysmotility disorder in which there’s a loss of ganglion cells in the lower esophagus; carries inc. risk of SCC
Three important inherited mitochondrial disorders
- Leber hereditary optic neuropathy –> bilateral vision loss
- Myoclonic epilepsy with ragged red fibers –> seizures and myopathy associated with exercise
- Mitochondrial encephalomyopathy with lactic acidosis and stroke-like symptoms (MELAS) –> kid has prior seizures, now with stroke like symptoms as well as myopathy (sister might not be as bad due to heteroplasmy)
Transference vs. Counter-transference
and Displacement
Transference is when a patient puts expectations/has feelings toward a physician that are not so much about the physician themself but rather about whoever in their past that the physician reminds them of; like a patient with daddy issues is upset when the physician cancels because he thinks he’s being abandoned again.
Counter-transference is when the physician does it to the patient; puts expectations on this based on people from the doc’s past.
Displacement = the chain of yelling
Opsoclonus-Myoclonus syndrome
- a syndrome of myoclonus, associated with rhythmic conjugate eye movements
- most often associated with neuroblastoma, which happens to be the most common extracranial childhood cancer in kids and peaks at 2yo
Paget Disease of Bone
Overactive Osteoclasts
*even though it’s diagnosed by inc. alk-phos (OBs) and really hard but lamellar bone; it originates because there’s overactive OCs for some reason, eating the bone, and the OBs have to react quickly and don’t make their best bone
Congenital CMV
seizures, ventriculomegaly, periventricular calcifications, sensorineural hearing loss, chorioretinitis
*TORCHeS infection
Post-Strep Glomerulonephritis
- hematuria + proteinuria + RBC casts in urine + hypercellular glomeruli on LM (from LC infiltration and endothe/mesangial proliferation)
- *Especially in a kid, after URI.
- Additional findings will include ASO Abs, anti-DNAse B, anti-cationic proteinase, and dec. C3 in serum
- On IF: coarse, granular deposits of IgG and C3
Jervell
Lange-Nielsen syndromes
These are congenital long QT syndromes that are associated with torsades and sensorineural deafness.
Other variants include Romano-Ward and Burgada.
Ortner syndrome
the impingement of the left recurrent laryngeal nerve that is caused by enlargement of the left atrium from say mitral stenosis
Henoch-Schönlein pupura
- small vessel vasculitis typically occurring in boys age 2-10; follows viral or strep URI
- thought to be IgA deposition mediated
- effects most prominently seen in GI (bleeding, edema, intussusception); kidney (crescent formation, mesangial proliferation); palpable purpura on buttocks and legs; and joints (self-limited arthralgias and arthritis in large joints)
Sequence of Hyperaldosteronism
- too much ALD produced, get Na retention, water follows, loss of K+/H+
- kidneys get high pressure inflow and secrete natriuretic peptide to compensate which dumps Na and H20
- leads to a limit to net sodium retention, avoidance of overt volume overload (so no edema, etc.)
- results in electrolyte imbalance enough to create paresthesias/muscle weakness, but on labs will see normal Na, low K, and low H/high bicarb (alkalosis)
Complications of OSA
- systemic HTN and pulmonary HTN - from chronic NE/SNS activity
- R heart failure (2/2 Pulm HTN)
- a-fib, arrhythmias, and coronary disease
- increased risk of stroke, SCD
Acute Intermittent Porphyria
deficiency of Porphobilinogen deaminase (converts Porphobilinogen to Urobilinogen)
5 P’s:
- painful abdomen
- port-wine colored urine
- polyneuropathy
- psychological disturbances
- precipitated by drugs (barbiturates)
Porphyria cutanea tarda
deficiency of Uroporphyrinogen decarboxylase (converts Uroporphyrinogen to Coproporphyrinogen)
- most common porphyria
- tea colored urine, blistering cutaneous photosensitivity
Ammonioagenesis
Glutamine is made in the liver and transported to the kidney (carries amino groups to get rid of)
Metabolized by ??????
into 2 bicarbs (reabsorbed to blood) and 1 NH4+ which is excreted (into lumen/urine)
Dysostosis Multiplex
mucopolysaccharide disorder: deficiency of beta-galactosidase, build-up of keratan sulfate/GM1; causes neurodegeneration, seizures, HSM, gait problems, joint problems, muscle weakness, skeletal irregularities
*think about Tay-Sachs, this can also get cherry-red macula (50%)
I cell disease
an LSD - defective addition of mannose-6-phosphate, so lysosomal enzymes aren’t targeted to the lysosome
- they are secreted instead and end up doing their activity outside the cell
- coarse facial features, clouded corneas, restricted joint movement, and high plasma levels of lysosomal enzymes
Caplan syndrome
Coal workers pneumoconiosis plus RA
Anthracosis
Carbon-laden MPs in the lungs (or lymph nodes) from urban exposure, benign
Myoedema
A localized swelling of the muscle that is secondary to slow reabsorption of Ca into the SR
Can be elicited by tapping the muscle with a reflex hammer.
If occurs in the setting of elevated CK, it’s highly suggestive of hypothyroidism; check TSH.
PKU
MCC is deficiency of phenylalanine hydroxylase, resulting in hyperphenylalanemia, hypopigmentation (no melanin for skin, eyes, hair, and catecholaminergic brain cells), intellectual disability, seizures, and musty body odor.
Could also be affected by BH4/dihydropteridine deficiency.
*In US it’s a newborn screen, so it won’t usually progress that bad, but an immigrant kid will probably present at 2-3yo
Congenital hypothyroidism
Either due to iodine deficiency or thyroid agenesis; baby will show signs of hypothyroidism around 2mo, since mom’s thyroxine from transplancetal transfer is there at first.
Thyroid hormone is needed for metabolism and brain development, hence intellectual disability; also see bulging anterior fontanel, bulging/protruding tongue, and bulging umbilical hernia. May also have swollen face from subcutaneous myxedema.
Partial vs. Complete mole
Partial = normal egg gets fertilized by 2 sperm; 69,XXY or 69,XXX; the extra set of chromosomes is always paternal in origin
Fetal tissue present with focally enlarged villi; focally hyperplastic trophoblasts
Complete = empty egg, usually gets fertilized by 1 sperm that duplicates, rarely fertilized by 2 sperm so more likely to see 46,XX
No fetal tissue present, diffusely enlarged villi, diffusely hyperplastic trophoblasts
Inguinal Hernia
Direct = through the peritoneum/abdominal wall weakness; medial to the epigastric vessels
Indirect = through the tunnel (deep inguinal ring); lateral to the epigastric vessels
–> Tunnel: FTFTA IOEO-AIL
Superficial inguinal ring is the opening in the external oblique aponeurosis
Rapidly Progressive Glomerulonephritis (RPGN)
3 causes:
- Anti-GBM/Goodpasture: will see IgG and C3 deposits on BM; may also have pulmonary hemorrhage/sx and will see decreased serum IgG/C3
- Immune Complex deposition: on IF there’s a lumpy-bumpy pattern of deposition of IgG and IgA; can be sequence of SLE, post-strep, Henoch-Schonlein, or IgA Nephropathy
- Pauci-Immune: no IF staining for antibodies, associated with Wegener’s and micropscopic polyangiitsi, so should look for ANCA; may also have URI involvement
Caudal regression syndrome
Congenital failure of lumbar spine/sacrum to develop – most commonly sacral agenesis but could be anal agenesis up to way more severe regression.
Highly associated with poorly controlled maternal DM.
Vitamin A overdose - congenital effects
- craniofacial and posterior fossa deformities
- auditory defects
- great vessel defects, similar to those in DiGeorge
Hepatitis E
- A/E are AcutE hepatitis, and fEcAl-oral route
- Hep E is unenveloped
- high mortality in pregnant women but NOT transmitted parenterally (see fecal-oral above)
Carcinoid syndrome vs. VIPoma
- Carcinoid syndrome = wheezing, diarrhea, facial flushing; from carcinoid tumor that has spread to liver (and has direct arterial access)
- VIPoma = WHDA
- *Symptoms of both can be treated with Octreotide which is a longer-lasting somatostatin analog; somatostatin controls not only GI substance release but also hormone release in general.
Treatment-Resistant Schizophrenia
- means they had poor response to at least 2 antipsychotics and continues to be symptomatic
- time for clozapine – but beware of neutropenia and agranulocytosis (also seizures and metabolic problems)
Dopamine hydroxylase deficiency
Deficiency of Da hydroxylase which normally makes Ne from DA; without it the pt will have dysautonomic characterized by ptosis, orthostatic HOTN, hypoglycemia, and hypothermia
Mixed Acid-Base disturbances
- The pt starts out with one type of acidosis/alkalosis; then the compensatory reaction decreases/fails
- In lactic acidosis/DKA will have to look for bicarb compensation; normal is a 1pt inc/2pt dec in bicarb for every 10pt change in CO2 (be that down or up, resp.); this can tell you if there’s a failure of respiratory compensation
- Will also have to look at kidney function to see if there’s a failure of metabolic compensation
- DKA can be precipitated by viral infection
Familial Dysbetalipoproteinemia vs. Familial Hyperlipidemia
Dysbeta = defective ApoE, can’t reuptake chylomicron/VLDL remnants; get eruptive xanthomas (palms/soles) and premature athero
HLD = defective ApoB100 and LDL-R, can’t reuptake LDL; get xanthelasma, tendon xanthomas, and premature athero
Familial Chylomicronemia vs. Familial Hypertriglyceridemia
Chylomicronemia = defective LPL and ApoC2; can’t reuptake chylomicrons
Hypertriglyceridemia = many proteins defective, can’t reuptake VLDL
Hemochromatosis
mutation in HFE gene/protein which is supposed to bring in the transferrin-Fe complex to add to the stores; if mutated it makes it look like you’re iron-deficient so 2 things happen:
1. enterocytes express more DMT1 on their apical surface to absorb Fe from the lumen
2. HCs decrease hepcidin expression, which normally would decrease ferroportin (on EC basolateral membrane)
and stop the transport of Fe into blood from EC
In infant:
Result of no Sertoli cells
Result of no Leydig cells
Sertoli cells produce MIF for inhibiting female internal genitalia (paramesonephric ducts); without it you get female internal genitalia.
Leydig cells produce Testosterone for promotion of Wolffian ducts and conversion into DHT for external male genital differentiation; without it there’s no internal or external male genitalia.
Hepatocellular carcinoma and Hepatitis B
MOA is unclear but it has to do with HepB having integrated into the DNA
Menier’s disease
accumulation of endolymph that causes excessive motion of the tectorial membrane and vertigo with hearing loss/tinnitus; causes recurrent episodes (as opposed to vestibular neuritis which is one viral/post-viral episode of vertigo only, no hearing loss)
Primary myelofibrosis
Atypical MKC hyperplasia which stimulates fibroblasts and replaces the bone marrow with fibrosis.
Sx include severe fatigue, HSM (which can cause abdominal discomfort/early satiety), anemia.
Caused by a JAK mutation.
Fragile X Syndrome
Prominent forehead and chin, long narrow jaw, large testes, speech/motor delay in infancy and/or neuropsychiatric issues in adolescence (ADHD, ASD, anxiety), and hyperlaxity of joints in the hands
Caused by small deletion/LOF mutation in the FMR1 gene on the long arm of the X chromosome
*females will have a milder presentation if heterozygous
Patau syndrome - clinical appearance
Trisomy 13:
rocker bottom feet, umbilical hernia/omphalocele, renal/cardiac defects, multiple fingers, cleft lip/palate, microphthalmia, microcephaly, and cutis aplasia (membrane-covered opening in scalp)
