Post on 29-Oct-2020
Initial Presentation• Presented to Comer ED s/p ALTE‐upper body stiffening &
apnea
• In ED: awake, decreased activity, able to breastfeed • Neuro consulted‐seizure unlikely• EKG marked prolonged QTc
• Ca 3.9 iCa 2.08 Ph 7
Mg 1.9
• Given Ca gluconate 50mg/kg then transferred to the PICU
HPI & ROS• T 100.4 four days prior, + sick contacts• Slightly decreased activity x 1 week, feeding well• Possible episode of foot “stiffening”
1 week prior
• Diet Hx• Mother: Vegan diet, no vitamin supplements, no prenatal
vitamin
• Pt: Exclusively breastfed until 6 mo, currently breastfeeds q2.5h
+ 1 jar baby food daily
• Received ~ 1hr/day of sunlight during 1st
few months
• ROS otherwise negative
PMH• Birth Hx
• Full term, 8 lbs 11 oz
• PMD at UIC, last seen at age 6 months• Unimmunized, takes no meds/vitamins
• Growing well, head circumference in upper percentile
• Nl development
History• FH
• No calcium, bone, kidney disorders, no short stature
• 2 yo brother on vegan diet, no hx of hypocalcemia
• SH• Lives with mother and brother
PE• Wt: 50th% Lt 75th% Wt‐for‐Lt 40th% HC 97th%
• Gen: decreased activity, awake• HEENT: no frontal bossing, + 2 lower central incisors, neg Chvostek sign
• CV: RRR, no m/r/g, 2+ periph pulses, no edema, no
costochondral knobs
• Resp: CTAB, no distress• GI: soft, NTND, no HSM• MSK: no widened wrists, no genu varum, no tetany
• Neuro: nl tone
Initial Labs• Ca 3.9 (9‐11) iCa 2.08 Ph 7 (4‐6.7) Mg 1.9 (1.3‐2) Alk phos 589 (100‐
390)
• Albumin 4.3 PTH 303
• 25‐OH vitamin D & 1,25‐vitamin D pending
• X‐rays wrist & knees: mild fraying of distal femur, ulna and prox.
fibular metaphysis
• Echo: normal (eval for DiGeorge syndrome)
Course• 25‐OH vitamin D <5 1,25‐vitamin D 18
• Diagnosis: Chronic vitamin D deficiency with subacute
calcium
deficiency• Similarity to Pseudohypoparathyroidism
• Meds• Ca gluconate
infusion max 400mg/kg/day x 2 days
• Calcitriol
0.05 mg/kg daily IV PO
• Ca Carbonate 150 mg/kg/day elemental
• Ergocalciferol
8000 IU daily
• EKG normal
• Discharge Ca 6.3 Ph 4.8 Alk
phos
461 (2 days prior, Ca 6.3)
Vit D def & PHP• Staging Vit
D‐deficiency rickets, Fraser 1967
• Stage 1: ↓Ca nl
Ph nl
urine a.a. & Ph
• Stage 2: nl
Ca ↓Ph ↑
urine a.a. & Ph
• Stage 3: ↓Ca ↓Ph ↑
urine a.a. & Ph
• PseudohypoPTH• Hypocalcemia
with elevated PTH and nl
renal function
• Mutation in alpha subunit of GNAS1
• hPTH
admin blunted urinary cAMP
and phos
• Types • Ia
& Ic: multiple hormone resistance + AHO phenotype, 1b – w/
phenotype
• II: renal resistance, no phenotype
Case Report: Vit D def vs PHP• Nl
23 mo boy with seizures and AED‐induced hypocalcemia
• Nl
electrolytes, Ca 6.4 mg/dL
(8.8‐10.8) P 6.7 mg/dL
(3.8‐6.5)
Mg 0.9 mmol/L (0.6‐0.95) Alk
phos
436 IU/L (145‐420) PTH
390.7 pg/mL
(11.1‐179)
• Urinary Ca:Cr
& tubular resorption
Ph nl, no aminoaciduria
• No rickets on L wrist x‐ray• Treated with Ca & high dose vit
D 3 weeks follow‐up Ca, Ph,
Alk
phos
nl.
Follow‐up• Increased solid food intake, now drinks sesame milk (Ca‐
containing)
• Ca 10.8 Ph 4.3 Alk phos 601 PTH 7 25‐OHVit D >100• 1, 25OH Vit D 279 (24‐86)• Currently taking MVI & ergocalciferol 4000 IU daily
References• Fraser D, Kooh SW, Scriver CR. Hyperparathyroidism as the
cause for hyperaminoaciduria and phosphaturia in human
vitamin D deficiency. Pediatr Res
1967; 1:425‐435
• Akin L, Kurtoglu S, Yildiz A, Akin MA. Vitamin D deficiency
rickets mimicking pseudohypoparathyroidism. J Clin Res Ped
Endo
2010: 2(4): 173‐175.