La afeccion hepatica leve neonatal que presento el propositus no ha sido descrita en otros casos de EOJA, es producto de dos deficiencias conjuntas del complejo multienzimatico mitocondrial de descarboxilasas de aminoacidos de cadena ramificada que encontramos en el propositus.
El higado, pero sobre todo el musculo, son organos importantes en la oxidacion y transaminacion de los aminoacidos de cadena ramificada, cuando existe un bloqueo metabolico por deficiencia del complejo enzimatico de las deshidrogenasas de estos alfa cetoacidos, se acumulan alfaoxoacidos e hidroxiacidos, asi como sus metabolitos, produciendo dano neuromuscular marcadamente en el propositus. El acumulo de cetoacidos tiene un efecto desmielinizante, lo que puede explicar porque el paciente tiene un deterioro neurologico severo.
The father of the propositus in family F had a low cobalamin concentration and low-normal TC I/HC and may thus have had mild TC I/HC deficiency, but this remains unconfirmed, as does the somewhat similar picture in the brother; their findings, like the borderline findings in the mother in family E, closely resemble the low-normal TC I/HC concentrations in the obligate heterozygote in family A (Table 1).
(a) Patient TC I/HC Plasma, Saliva, Cobalamin, pmol/L nmol/L pmol/L Family A Propositus 0 (b) 0 (b) 65 (c) Daughter (a) 169 21.5 - (c) Family B Propositus 1 (e) Absent Absent Low Propositus 2 (e) 0 (b) 0 (b) 39 Brother of both propositi (f) 98 23.1 157 Son of propositus 1 (d) 74 24.2 139 Son of propositus 2 (d) 111 19.4 127 Reference interval 165-454 6.5-98.1 140-750 (a) The propositus in family A was found during the survey to have classic severe TC I/HC deficiency in this study (lactoferrin concentrations were within the reference interval).
For the isolated Hb fractions from the propositus, the precipitation was 88% in the Hb Xo fraction and 68% in the Hb [A.sub.0] fraction after 15 min; for the hemolysate from a healthy individual, in which the Hb concentration was adjusted to that of the Hb fractions, the precipitation was 61%.
DNA analysis of the propositus revealed heterozygosity for a C[right arrow]G transversion at codon 5 of the [beta]-globin gene, which replaces proline with alanine (CCT[right arrow]GCT; 05Pro[right arrow]Ala).
(a) Patient Genotype Genotype determined determined by PCR-RFLP by sequence analysis Paternal aunt MM M[M.sub.Heerlen] Mother MZ MZ Propositus
MZ [M.sub.Heerlen]Z Sister MZ [M.sub.Heerlen]Z Niece MM [MM.sub.Heerlen] Nephew MM [MM.sub.Heerlen] Patient Phenotype Serum determined AAT, g/L by IEF (0.8-2.0) (b) Paternal aunt ND (c) ND Mother MZ 1.1 Propositus
Z 0.3 Sister Z 0.4 Niece M 1.2 Nephew M 0.9 (a) Both the DNA-based PCR-RFLP test as well as IEF yield improper results if the [M.sub.Heerlen] allele is present.
For sequencing of CD13 cDNA, whole blood was collected from the propositus
(40-year-old woman) of a family described previously (1).
Direct sequencing of the amplified DNA from the propositus
confirmed the nucleotide change from GGT to GAT at codon 69 of the [beta]-gene, which corresponds to a Gly[right arrow]Asp replacement at position 69.
It was speculated that the FVII of the propositus
, which has different activation patterns for TFs from different sources, might possess substitution of Arg 79 or Gln 304.
Serum samples were collected from the propositus
, her father, mother, paternal grandmother, and younger sister, none of whom had any particular disease, and an unrelated healthy volunteer (a 37-year-old man) as a control.
Serum ALT activity of the propositus
' parents and his brother and sisters was within reference limits.