2025 – PAGE 361 – INBORN ERRORS OF METABOLISM & MISCELLANEOUS METABOLIC DISORDERS

MENKES KINKY HAIR SYNDROME (AKA MENKES SYNDROME)

In Menkes Kinky Hair syndrome, look for low copper levels and low ceruloplasmin levels (like in Wilsons Disease). The patient also has high TISSUE copper. Patients get kinky and twisted hair. It’s X-linked.

MNEMONIC: X-linked. Who watches XXX movies? Kinky boys!

SMITH-LEMLI-OPITZ SYNDROME

In Smith-Lemli-Opitz syndrome, there is defective cholesterol synthesis. Associated with cognitive deficits/intellectual disability, microcephaly, and various organ malformations (possibly ambiguous genitalia). The patient also has 2-3 toe syndactyly (fused) in which they look like a “Y”. Since it is a cholesterol metabolism issue, there will be an elevated 7-dehydrocholesterol.

IMAGE: www.pbrlinks.com/SLO1

MNEMONIC: smYth lemlY opYtz since they look like a “Y.”

CHERRY RED SPOT DIFFERENTIAL

The differential for a cherry red spot includes Tay-Sachs Disease, Niemann-Pick Disease and Farber’s Disease (Farber’s Disease is low-yield).

• TAY-SACHS: Ashkenazi Jews. Macrocephaly, abnormal Moro to noise or light, motor regression.
• SANDHOFF: Very similar to Tay-Sachs, but not in Ashkenazi Jews, and can also have hepatosplenomegaly. These kids are developmentally normal until age 3-6 months, and then start regressing.
• NIEMANN-PICK: Hepatosplenomegaly and neurologic problems. In Type A, infants are developmentally delayed before age 3 months.
• FARBER’S DISEASE (AKA DISSEMINATED LIPGRANULOMATOSIS): Probably low-yield because it’s extremely rare. Progressive disease. Fatal within the first few years. Look for a baby with joint pain and skin nodules presenting within the first week of life.
  • MNEMONICS FOR THE “CHERRY RED SPOT” DISORDERS:
  • Imagine a CHERRY FARMER going to NIEMANN Marcus in his overalls, first brushing the SAND HOFF, to try and sell a SACH of cherries to them! Wow, talk about rough economy.
    KEY: Cherry, Farber, Niemann-Pick, Tay-SACH.

• • CHERRY FARMER’S disease = Imagine a CHERRY FARMER working so hard that he gets ARTHRITIS and SWOLLEN BUG BITES all over his skin.

• RETINAL ARTERYOCCLUSION: Presents as painless visual loss with a cherry red spot at macula.
  • (NAME ALERT) RETINAL VEIN OCCLUSION: Painless visual loss with multiple hemorrhages noted on ophthalmologic exam, referred to as having a “thunder and lightning” appearance. Sometimes also referred to as “blood and thunder” or “pizza pie.”
    • MNEMONIC: Venous blood is dark. Thunder and lightning occur at night.
  • (NAME ALERT) RETINAL DETACHMENT: Visual loss with what looks like cobwebs or a curtain coming across a patient’s vision.
    • MNEMONIC: Imagine the retina being really far back in the eye in an area where COBWEBS are growing on old CURTAINS.