Page 734 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat

690 SeCTiON iii Rapid Review ` ClassiC Presentations Rapid Review ` ClassiC Presentations

` ClassiC Presentations

CliniCal Presentation DiaGnosis/Disease PaGe
Gout, intellectual disability, self-mutilating behavior in a Lesch-Nyhan syndrome (HGPRT deficiency, X-linked 37
boy recessive)
Situs inversus, chronic sinusitis, bronchiectasis, infertility Kartagener syndrome (dynein arm defect affecting cilia) 49
Blue sclera Osteogenesis imperfecta (type I collagen defect) 51

Elastic skin, hypermobility of joints,  bleeding tendency Ehlers-Danlos syndrome (type V collagen defect, type III 51
collagen defect seen in vascular subtype of ED)
Arachnodactyly, lens dislocation (upward and temporal), Marfan syndrome (fibrillin defect) 52
aortic dissection, hyperflexible joints
Café-au-lait spots (unilateral), polyostotic fibrous McCune-Albright syndrome (G -protein activating 57
s
dysplasia, precocious puberty, multiple endocrine mutation)
abnormalities
Calf pseudohypertrophy Muscular dystrophy (most commonly Duchenne, due to 61
X-linked recessive frameshift mutation of dystrophin
gene)
Child uses arms to stand up from squat Duchenne muscular dystrophy (Gowers sign) 61
Slow, progressive muscle weakness in boys Becker muscular dystrophy (X-linked non-frameshift 61
deletions in dystrophin; less severe than Duchenne)
Infant with cleft lip/palate, microcephaly or Patau syndrome (trisomy 13) 63
holoprosencephaly, polydactyly, cutis aplasia
Infant with microcephaly, rocker-bottom feet, clenched Edwards syndrome (trisomy 18) 63
hands, and structural heart defect
Single palmar crease Down syndrome 63
Dilated cardiomyopathy, edema, alcoholism or Wet beriberi (thiamine [vitamin B ] deficiency) 66
1
malnutrition
Dermatitis, dementia, diarrhea Pellagra (niacin [vitamin B ] deficiency) 67
3
Swollen gums, mucosal bleeding, poor wound healing, Scurvy (vitamin C deficiency: can’t hydroxylate proline/ 69
petechiae lysine for collagen synthesis)
Chronic exercise intolerance with myalgia, fatigue, McArdle disease (skeletal muscle glycogen phosphorylase 87
painful cramps, myoglobinuria deficiency)
Infant with hypoglycemia, hepatomegaly Cori disease (debranching enzyme deficiency) or Von 87
Gierke disease (glucose-6-phosphatase deficiency, more
severe)
Myopathy (infantile hypertrophic cardiomyopathy), Pompe disease (lysosomal α-1,4-glucosidase deficiency) 87
exercise intolerance

“Cherry-red spots” on macula Tay-Sachs (ganglioside accumulation) or Niemann-Pick 88
(sphingomyelin accumulation), central retinal artery
occlusion
Hepatosplenomegaly, pancytopenia, osteoporosis, Gaucher disease (glucocerebrosidase [β-glucosidase] 88
avascular necrosis of femoral head, bone crises deficiency)
Achilles tendon xanthoma Familial hypercholesterolemia ( LDL receptor signaling) 94
Anaphylaxis following blood transfusion IgA deficiency 116
Male child, recurrent infections, no mature B cells Bruton disease (X-linked agammaglobulinemia) 116

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