Cairney, A. E.

Prasad, Chitra

Rosenblatt, D. S.

Rupar, C. A.

English

Scholarship@Western

Western University Scholarship@Western Paediatrics Publications Paediatrics Department 7-1-2012 Transcobalamin (TC) deficiency and newborn screening Chitra Prasad London Health Sciences Centre A. E. Cairney London Health Sciences Centre, beth.cairney@lhsc.on.ca D. S. Rosenblatt Université McGill C. A. Rupar London Health Sciences Centre Follow this and additional works at: https://ir.lib.uwo.ca/paedpub Citation of this paper: Prasad, Chitra; Cairney, A. E.; Rosenblatt, D. S.; and Rupar, C. A., "Transcobalamin (TC) deficiency and newborn screening" (2012). Paediatrics Publications. 921. https://ir.lib.uwo.ca/paedpub/921 LETTER TO THE EDITORSTranscobalamin (TC) deficiency and newborn screeningChitra Prasad & A. E. Cairney & D. S. Rosenblatt &C. A. RuparReceived: 16 October 2011 /Revised: 22 November 2011 /Accepted: 23 November 2011 /Published online: 14 December 2011# SSIEM and Springer 2011Dear Editor,We would like to update the readership about transcobala-min (TC) deficiency and newborn screening. In a recentarticle we described two siblings with TC deficiency (Prasadet al. 2008). The older child was clinically symptomatic withpancytopenia and his sister was diagnosed at birth by mu-tation analysis. Both children were homozygous for aR399X (c.1195C>T) mutation. Both children are now doingwell on oral Vitamin B12 (Cyanocobalamin 10 mg and 5 mgonce daily respectively). Propionylcarnitine concentrationswere not elevated in the newborn screening cards from theproband and sister, however as indicated in Prasad et al.2008, the analyses were performed on specimens retrievedfrom storage after 7 years and 5 years, respectively. Themother has delivered another son who is clinically asymp-tomatic at age 5 months but had a positive newborn screenfor propionic/methylmalonic acidemia with an elevated C3at 6.59 μM (0.68-3.9) and C3/C200.33. The Ontario pro-vincial newborn screening program considers a result posi-tive for a baby <7 days old if C3/C2 >0.27 and C3 >4.0 μMor the C3/C2>0.23 and C3 >5.5 μM. Hematological param-eters showed low hemoglobin at 145 (150–200 g/L) andneutrophils at 4.1 (6–26 )×10*9/L. Platelets were normal at425 (150–400)×10*9/L and homocysteine was 18.1 (5–12/L) mildly elevated. Oral Vitamin B12 1 mg daily (Cyanoco-balamin) was initiated based on the positive newbornscreening results and the diagnosis of TC deficiency wasconfirmed by mutation analysis. In a paper by Ratschmannet al. 2009, TC deficiency was diagnosed in one of thesiblings at birth by measuring TC protein in the umbilicalcord however it was not mentioned if newborn screeningwas done on that affected baby.Our experience indicates that infants with TC deficiencymay be identified by C3 elevation on tandem mass spec-trometry newborn screening and that TC deficiency shouldbe kept in differential diagnosis when elevated C3 isencountered.ReferencesPrasad C, Rosenblatt DS, Corley K, Cairney AE, Rupar CA (2008)Transcobalamin (TC) deficiency-Potential cause of bone marrowfailure in childhood. J Inherit Metab Dis 31(Suppl 2):S287–292Ratschmann R, Minkov M, Kis A, Hung C, Rupar T, Mühl A, FowlerB, Nexo E, Bodamer OA (2009) Transcobalamin II deficiency atbirth. Mol Genet Metab 98(3):285–288Communicated by: Georg HoffmannCompeting interest: None declared.C. Prasad (*) :A. E. Cairney : C. A. RuparLondon Health Sciences Centre,London, Ontario, Canadae-mail: Chitra.Prasad@lhsc.on.caD. S. RosenblattDepartment of Human Genetics, McGill University,Quebec, CanadaJ Inherit Metab Dis (2012) 35:727DOI 10.1007/s10545-011-9431-4

Transcobalamin (TC) deficiency and newborn screening

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