Molecular and clinical consequences of novel mutations in the arylsulfatase A gene.

Metachromatic leukodystrophy (MLD), a severe neurodegenerative metabolic disorder, is caused by deficient activity of arylsulfatase A (ARSA; EC 3.1.6.8), which leads to a progressive demyelinating process in central and peripheral nervous systems. In this study, a DNA sequence analysis was performed on six Polish patients with different types of MLD. Six novel mutations were identified: one nonsense (p.R114X), three missense (p.G122C, p.G293C, p.C493F) and two frameshift mutations (g.445_446dupG and g.2590_2591dupC). Substitutions p.G293C and p.C493F and duplication g.445_446dupG caused a severe reduction of enzyme activity in transient transfection experiments on mammalian cells (less than 1% of wild-type (WT) ARSA activity). Duplication 2590_2591dupC preserved low-residual ARSA activity (10% of WT ARSA). In summary, the novel MLD-causing mutations in the exons 2, 5 and even in 8 of the ARSA gene described here can be classified as severe type 0, leading in homozygosity to the late infantile form MLD. Growth retardation, delayed motor development, gait disturbances, tonic-clonic seizures and non-epileptic muscle spasms were the first onset symptoms in patients with late infantile form of MLD. In individual with juvenile type MLD gait disturbances evidenced the onset of the disease, while in a patient with late juvenile MLD, difficulties at school were displayed.

A case with 47,XXY,del(11)(q23) karotype-coexistence of Jacobsen and Klinefelter syndromes.

A case with 47,XXY, del(11)(q23) karyotype-coexistence of Jacobsen and Klinefelter syndromes: A two-year-old dysmorphic male child was found to have 47,XXY,del(11)(q23) karyotype. Domination of the clinical features of Jacobsen syndrome was observed: mild mental retardation, trigonocephaly, ptosis, downward slanting palpebral fissures, low set ears, carp-shape mouth and micrognathia. Transient thrombocytopenia and leukopenia were also present. Over the following five years gynecomastia and eunuchoid body proportions became evident as clinical features of Klinefelter syndrome. This is the first description of the coexistence of both syndromes.