Dyslipidemia and hypercalciuria in a patient with pantothenate kinase 2 deficiency: A novel variant and case report.

Pantothenate kinase-associated neurodegeneration (PKAN, OMIM: 234200) results from biallelic pathogenic variants in PANK2 which encodes pantothenate kinase 2, a crucial mitochondrial enzyme involved in coenzyme A biosynthesis. Pantothenate kinase-associated neurodegeneration patients typically exhibit the distinctive "eye of the tiger" sign on brain magnetic resonance imaging in the globus pallidus, along with psychiatric symptoms, extrapyramidal movements such as parkinsonism and dystonia, eventual speech and gait impairments, and the presence of dysphagia. An 11-year-old girl, with fifth-degree consanguinity, demonstrated typical psychomotor development and growth until the age of 5, when she began experiencing psychiatric symptoms. At the age of 9, she developed hand tremors, progressing to generalized muscular dystonia. By age 10, she exhibited gait and speech impairment. Physical examination revealed extensive generalized dystonia, hand tremors, speech impairment, dysphagia, inability to walk, and heightened osteotendinous reflexes. Metabolic analysis identified dyslipidemia with partial response to statin treatment and normocalcemic hypercalciuria. Exome sequencing revealed a novel likely pathogenic variant in PANK2 (NM_001386393.1:c.526C > G) in a homozygotic state. Pantothenate kinase-associated neurodegeneration typically manifests with generalized dystonia and psychiatric symptoms. Here, we present a Pantothenate kinase-associated neurodegeneration patient with dyslipidemia and hypercalciuria as potentially previously undescribed metabolic phenotype.

Characterization of novel GCDH pathogenic variants causing glutaric aciduria type 1 in the southeast of Mexico.

Biallelic mutations of the GCDH gene result in Glutaric Aciduria type 1 (GA1; OMIM #231670), an uncommon autosomal recessive inborn error caused by the deficiency of glutaryl-CoA dehydrogenase (CCDH), a mitochondrial matrix protein involved in the degradation of l-lysine, L-hydroxylysine, and L-tryptophan. The enzymatic deficiency leads to the accumulation of neurotoxins causing macrocephaly at birth, hypotonia and dystonia due to bilateral striatal injury, that evolves with aging, if untreated, to fixed dystonia and akinetic-rigid parkinsonism. In this article, we describe the results of molecular studies of 5 unrelated patients with GA1 in Southern Mexico. Mutational analysis identified 2 novel likely pathogenic GCDH variants (p.Leu130Pro and p.Gly391Val), 1 pathogenic variant that is predicted to cause a premature stop codon (p.Leu370*), and 2 previously reported pathogenic variants (p.Arg294Trp and p.Arg294Gln). The recurrence of the p.Leu130Pro variant (60% of mutant alleles) suggested a possible founder mutation effect. Our results expand the mutational spectrum in GA1 patients and support the importance of early diagnosis through newborn screening that promotes early nutritional treatment and prevents metabolic crisis. TAKE HOME MESSAGE: Glutaric Aciduria type 1 has a wide mutational spectrum; the p.Leu130Pro variant may be a founder mutation in Southeast Mexico.

Newborn cystic fibrosis screening in southeastern Mexico: Birth prevalence and novel CFTR gene variants.

OBJECTIVE: To use the results of the first five years of a cystic fibrosis newborn screening program to estimate the cystic fibrosis birth prevalence and spectrum of cystic fibrosis transmembrane conductance regulator ( CFTR) gene variants in Yucatan, Mexico. METHODS: Screening was performed from 2010 to 2015, using two-tier immunoreactive trypsinogen testing, followed by a sweat test. When sweat test values were >30 mmol/L, the CFTR gene was analyzed. RESULTS: Of 96,071 newborns screened, a second sample was requested in 119 cases. A sweat test was performed in 30 newborns, and 9 possible cases were detected (seven confirmed cystic fibrosis and two inconclusive). The most frequently detected CFTR pathogenic variant (5/14 cystic fibrosis alleles, 35.7%) was p.(Phe508del); novel p.(Ala559Pro) and p.(Thr1299Hisfs*29) pathogenic variants were found. CONCLUSIONS: Cystic fibrosis birth prevalence in southeastern Mexico is 1:13,724 newborns. Immunoreactive trypsinogen blood concentration is influenced by gestational age and by the time of sampling. The spectrum of CFTR gene variants in Yucatan is heterogeneous.