Screening of LDLR and APOB gene mutations in Mexican patients with homozygous familial hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant disorder that causes accumulation of serum low-density lipoprotein cholesterol and premature cardiovascular disease. It is mainly related to mutations in the LDLR gene. Homozygous FH (HoFH) patients have the most severe form of the disease accounting for a worldwide prevalence of 1:1,000,000. In Mexico, at least 5 cases of HoFH have been reported. OBJECTIVE: The aim of this study was to describe the clinical, biochemical, and molecular data observed in patients with HoFH phenotype. METHODS: We included 13 patients, belonging to 11 families, with clinical and biochemical diagnoses suggestive of HoFH. Molecular analyses of the LDLR and APOB genes were performed by means of polymerase chain reaction followed by Sanger sequencing. RESULTS: The causal mutation of HoFH was found in 8 of 11 unrelated patients. Excepting 1, all were true homozygotes. Six different variants in LDLR were identified: c.-139delCTCCCCCTGC, p.Glu140Lys, p.Asp360His, p.Asn405Lys, p.Ala755Glyfs*7, and p.Leu759Serfs*6. Of these, p.Asp360His and p.Asn405Lys were detected for the first time in Mexico; p.Leu759Serfs*6 showed to be the most frequent (43.7% of the alleles 7/16), and c.-139delCTCCCCCTGC is a new variant located in the promoter region. CONCLUSIONS: This work increases knowledge of biochemical and genetic features in Mexican patients with HoFH. A novel mutation in the LDLR gene promoter was detected: c.-139delCTCCCCCTGC, which possibly inhibits its expression.

Estenosis pulmonar valvular crítica del recién nacido; valvuloplastía con globo efectuada usando un asa arterio-venosa y dilataciones secuenciales / Critical pulmonary valve stenosis in neonates; its treatment with ballon valvuloplasty using and arteriovenous loop and gradational dilatations

La estenosis pulmonar valvular crítica del recién nacido es una urgencia donde la valvuloplastía puede representar su corrección definitiva. Este recurso tiene particularidades técnicas importantes, relacionadas a la edad y peso del paciente, y a factores anatómicos que contribuyen a la obstrucción. Se presenta el caso de un neonato de 20 días con este problema, en el que el empleo de una asa arterio-venosa a través del conducto arterioso permitió el paso de globos con diámetro progresivamente mayor hasta llegar a la relación globo/anillo de 1.4. Este abordaje puede emplearse con seguridad en casos donde existan dificultades para aplicar la técnica habitual y permite lograr la dilatación valvular adecuada