Molecular analyses of novel ASAH1 mutations causing Farber lipogranulomatosis: analyses of exonic splicing enhancer inactivating mutation.

Farber lipogranulomatosis is a rare autosomal recessive lysosomal storage disorder caused by mutations in the ASAH1 gene. In the largest ever study, we identified and characterized ASAH1 mutations from 11 independent Farber disease (FD) families. A total of 13 different mutations were identified including 1 splice, 1 polypyrimidine tract (PPT) deletion and 11 missense mutations. Eleven mutations were exclusive to the Indian population. The IVS6+4A>G splice and IVS5-16delTTTTC PPT deletion mutations resulted in skipping of exon 6 precluding thereby the region responsible for cleavage of enzyme precursor. A missense mutation (p.V198A) resulted in skipping of exon 8 due to inactivation of an exonic splicing enhancer (ESE) element. This is the first report of mutations affecting PPT and ESE in the ASAH1 gene resulting in FD.

Endosulfan and flutamide, alone and in combination, target ovarian growth in juvenile catfish, Clarias batrachus.

Juvenile Catfish(es), Clarias batrachus of 50 days post hatch (dph) were exposed to endosulfan (2.5 parts per billion [ppb]) and flutamide (33 ppb), alone and in combination for 50 days to access their impact on ovarian development. The doses used in this study were nominal considering pervious reports. Sampling was done at 100 dph to perform histology and measurement of various transcripts, estradiol-17ß and aromatase activity. In general, treatments enhanced expression of ovary-specific transcription factors, steroidogenic enzymes steroidogenic acute regulatory protein and aromatases while transcripts of tryptophan hydroxylase2 (tph2) and catfish gonadotropin-releasing hormone declined in the brain of all treated groups with maximum reduction in the endosulfan group. Significant reduction of tph2 immunoreactivity in the forebrain/telencephalon-preoptic area endorsed our results. Increased number of pre-vitellogenic and less immature oocytes in the treated groups indicated hastened ovarian growth. Elevated ovarian aromatase activity and plasma estradiol-17ß levels were noticed in the treated groups with maximum being in the endosulfan group. These data together demonstrate that the exposure of endosulfan causes synchronous precocious ovarian development better than flutamide, alone or in combination. Our results suggest that both endosulfan and flutamide alter ovarian growth by triggering precocious development in catfish.

A founder ectodysplasin A receptor (EDAR) mutation results in a high frequency of the autosomal recessive form of hypohidrotic ectodermal dysplasia in India.

BACKGROUND: Hypohidrotic/anhidrotic ectodermal dysplasia (HED) is a rare Mendelian disorder affecting ectodermal tissues. The disease is primarily caused by inactivation of any one of three genes, namely ectodysplasin A1 (EDA-A1), which encodes a ligand belonging to the tumour necrosis factor (TNF) superfamily; ectodysplasin A receptor (EDAR), encoding the EDA-A1 receptor and ectodysplasin A receptor-associated death domain (EDARADD), encoding an adaptor protein. X-linked recessive (EDA-A1), the predominant form of HED, as well as autosomal recessive and dominant (EDAR and EDARADD) inheritance patterns have been identified in affected families. OBJECTIVES: To determine the common genes causing HED in India. METHODS: We performed mutation analysis on 26 HED families from India (including 30 patients). In addition, we carried out sequence and structural analysis of missense/nonsense and insertion/deletion mutations. RESULTS: Among the 26 families analysed, disease-causing EDAR mutations were identified in 12 (46%) while EDA-A1 mutations were detected in 11 (42%). Four novel mutations in EDAR and five in EDA-A1 were identified. More importantly, a possible founder EDAR mutation, namely c.1144G>A, was identified in five independent families, thus accounting for about one-fifth of affected families in whom mutation was detected. A majority of EDA-A1 mutations localized to the TNF-like domain while the location of EDAR mutations was more widespread. CONCLUSIONS: This is the first report of a founder EDAR mutation and of a significantly high frequency of autosomal recessive HED.

Molecular analysis of autosomal dominant hereditary ataxias in the Indian population: high frequency of SCA2 and evidence for a common founder mutation.

Expansion of CTG/CAG trinucleotide repeats has been shown to cause a number of autosomal dominant cerebellar ataxias (ADCA) such as SCA1, SCA2, SCA3/ MJD, SCA6, SCA7, SCA8 and DRPLA. There is a wide variation in the clinical phenotype and prevalence of these ataxias in different populations. An analysis of ataxias in 42 Indian families indicates that SCA2 is the most frequent amongst all the ADCAs we have studied. In the SCA2 families, together with an intergenerational increase in repeat size, a horizontal increase with the birth order of the offspring was also observed, indicating an important role for parental age in repeat instability. This was strengthened by the detection of a pair of dizygotic twins with expanded alleles showing the same repeat number. Haplotype analysis indicates the presence of a common founder chromosome for the expanded allele in the Indian population. Polymorphism of CAG repeats in 135 normal individuals at the SCA loci studied showed similarity to the Caucasian population but was significantly different from the Japanese population.