Table 2. Molecular studies in patients with primary carnitine deficiency.

Sequencing and deletion/duplication analysis of all 10 exons of the SLC22A5 gene and flanking regions was performed in 95 patients diagnosed with primary carnitine deficiency because of a low level of carnitine transport in fibroblasts (activity <20% of matching normal controls). No variants were identified in 31/190 (16%) of the alleles sequenced. For 6/95 (6%) affected patients no variants were identified in either alleles, while for 19/95 (20%) affected patients no variant was identified in one allele.

NUMBER of PATIENTS	95
NUMBER of ALLELES	190
Alleles with unknown mutations	31/190 (16%)
Patients with no identified variant in one allele	19/95 (20%)
Patients with no identified variant in either alleles	6/95 (6%)