Male infertility: risk factors in Mongolian men.

AIM: To determine the most common risk factors of male infertility in Mongolian men attending an infertility clinic. METHODS: A prospective, case-control study was conducted in which 430 men were enrolled. All the men had sought their first infertility evaluation between 1998-2002 in the State Research Center on Maternal Child Health, Ulaanbaatar, Mongolia. They were divided into two groups depending on the results of their semen analysis: 191 with abnormal semen and 239 with normal semen profile. Univariate and multivariate analyses were performed to determine any association between risk factors and semen abnormality. RESULTS: Logistic regression analysis demonstrated that the testicular volume, a history of sexually transmitted infections (STI), epididymitis and testicular damage all have statistically significant associations with semen abnormality, when controlled for multiple risk factors. Adjusted odds ratios of 3.4 for mumps orchitis, 2.3 for other orchitis and 3.9 for testicular injury were found. Gonorrhoea, the most commonly reported STIs in this study, gave an adjusted odds ratio of 1.0 for having one or more sperm abnormality. An adjusted odds ratio for subjects with a history of other STIs was 2.7. However, as a predictor of azoospermia, STIs had very high odds ratio, being 5.6 in patients with gonorrhoea and 7.6 in patients with other STIs. CONCLUSION: A history of pathology involving testicular damage appeared to have the strongest impact on male infertility in Mongolia. STIs have less impact on semen quality except when complicated by orchitis, epididymitis and vasal obstruction.

Origins and frequencies of SLC26A4 (PDS) mutations in east and south Asians: global implications for the epidemiology of deafness.

Recessive mutations of SLC26A4 (PDS) are a common cause of Pendred syndrome and non-syndromic deafness in western populations. Although south and east Asia contain nearly one half of the global population, the origins and frequencies of SLC26A4 mutations in these regions are unknown. We PCR amplified and sequenced seven exons of SLC26A4 to detect selected mutations in 274 deaf probands from Korea, China, and Mongolia. A total of nine different mutations of SLC26A4 were detected among 15 (5.5%) of the 274 probands. Five mutations were novel and the other four had seldom, if ever, been identified outside east Asia. To identify mutations in south Asians, 212 Pakistani and 106 Indian families with three or more affected offspring of consanguineous matings were analysed for cosegregation of recessive deafness with short tandem repeat markers linked to SLC26A4. All 21 SLC26A4 exons were PCR amplified and sequenced in families segregating SLC26A4 linked deafness. Eleven mutant alleles of SLC26A4 were identified among 17 (5.4%) of the 318 families, and all 11 alleles were novel. SLC26A4 linked haplotypes on chromosomes with recurrent mutations were consistent with founder effects. Our observation of a diverse allelic series unique to each ethnic group indicates that mutational events at SLC26A4 are common and account for approximately 5% of recessive deafness in south Asians and other populations.

Mutation in the mitochondrial 12S rRNA gene in two families from Mongolia with matrilineal aminoglycoside ototoxicity.

Irreversible hearing loss is a catastrophic complication of treatment with aminoglycoside antibiotics such as streptomycin, gentamycin, and kanamycin. Many kindreds showing a matrilineal pattern of inheritance of this trait have been described in China where the widespread use of aminoglycoside antibiotics accounts for approximately 25% of profound deafness in some districts. Because of the characteristic inheritance pattern, mitochondrial DNA (mtDNA) mutations were postulated to be the cause of the deafness in these pedigrees. In 1993 it was shown that an A to G substitution at base pair 1555 of the mitochondrial 12S ribosomal RNA gene was the only mutation common to all the families with aminoglycoside ototoxicity. We ascertained three Mongolian pedigrees from the School for the Deaf and Blind in Ulaanbaatar, all of which contained multiple affected subjects with streptomycin induced deafness in a pattern consistent with matrilineal transmission. Amplified mtDNA, obtained from transformed lymphoblastoid cell lines using previously described primers, showed the A to G point mutation in the 12S rRNA gene in two of the three families by restriction analysis as well as direct sequencing. No other example of this substitution was found among 400 control samples from Mongolians with normal hearing. We have thus confirmed the clinical relevance of the 1555 A to G mitochondrial mutation in the 12S rRNA gene by identifying it in affected subjects with familial aminoglycoside ototoxicity in another ethnic group. In countries where aminoglycosides are widely used, genetic counselling and screening of high risk families before the use of these drugs could have a dramatic effect on the incidence of deafness.

Mongolia: demographic characteristics reflect current pro-natalist policies.

PIP: The population of the Mongolian People's Republic is rapidly increasing due to the high birthrate, encouraged by the pronatalist policies of the government, a marked decline in the death rate following the revolution, and a further decline in the death rate due to improvements in health services. In 1918 the population was 542,000, in 1940, 738,000, in 1960, 936,900, and in 1980, 1,639,700. In the last 60 years the population tripled. At the present time there are a little over 1.8 million people living in Mongolia's 1,555,000 square kilometers of land. In 1980 the birthrate was 378/1000 population, the death rate was 104/1000 population, and 274,000 people were added to the population in 1980. These changes have altered the age and sex distribution of the population. An estimated 47% of the population in 1982 was less than 17 years of age. The increase in young people has rejuvenated the working sector. There has been a marked change in the socioeconomic structure of the country as evidenced in the proportional changes in social group membership. Between 1956-79 the percent of the population composed of workers, employees, and their families increased from 25.9% to 61.7%, the percent composed of members of agarian and artisan cooperatives and their families increased from 11.1% to 38.1%. During the same period the percent of the population composed of livestock breeders and non-cooperated artisans and their families decreased from 62.8% to 0.2%. Rapid industrialization has also lead to a marked increase in the urban population. Tables provide information on 1) birth, death and population growth rates for 1955-80; 2) percent of urban and rural population for 1950-1980; 3) population by social groups 1956-1979; and 4) total population figures for 1918-79.^ieng