PubMed Health⌕ Search

Biomedical subjects

K Kucheria

Publications and source records attributed to K Kucheria.

At least 19 recordsLinked to original sources
PubMed2006

Cytogenetic and molecular analysis of male infertility: Y chromosome deletion during nonobstructive azoospermia and severe oligozoospermia.

Reduced male fertility and subfertility can be caused by genetic factors that affect both germ cell development, differentiation, and function; in particular, chromosome abnormalities and Yq microdeletions are a possible cause of spermatogenetic impairment in males as shown by their higher frequency in infertile men than in the general male population. Microdeletion of the long arm of the Y chromosome (Yq) are associated with spermatogenic failure and have been used to define three regions on Yq (AZFa, AZFb, and AZFc) that are critical for germ cell development. With the advent of assisted reproductive technology and intracytoplasmic sperm injection, knowledge about the various factors leading to spermatogenic impairment is one of the most important aspects of scientific research. Therefore, this study was designed to identify the frequency of cytogenetic and submicroscopic interstitial deletions in azoospermia factor loci in infertile Indian males. One hundred and eighty males with nonobstructive oligozoospermia and azoospermia were included in this study. Semen analysis was done in each case to determine the spermatogenic status. Individuals were subjected to detailed clinical examination, family history, and endocrinological and cytogenetic study after consent from the patient. Peripheral blood cultures were set up according to standard protocols and 30 G-banded metaphases were analyzed in each case. Numerical and structural chromosomal abnormalities were detected in 40 infertile cases. Fluorescence in situ hybridization analysis was done in some cases to identify the percentage of mosaic cell lines and any cryptic or low-level mosaicism. Polymerase chain reaction microdeletion analysis was done in 140 cytogenetically normal cases. Of the 140 cases, 8 showed deletion of at least one of the sequence-tagged site markers. Review of literature has shown that the overall frequency of microdeletions varies from 1 to 55%. In the present study, the frequency of microdeletion was 5.8%, and deletions were identified in cases with undescended testis and varicocele and cases with bilateral severe testiculopathy.

Chromosome Deletion↗
PubMed2005

A 2-year-old baby with Downs syndrome, cryptorchidism and testicular tumour.

Seminomas are rare germ cell tumours. It occurs usually in men aged over 50 years. Seminomas differ genetically and clinically from germ cell tumours. They have a late age of onset and rarely metastasise. The incidence of testicular carcinoma (seminoma) in patients of Down syndrome has recently been emphasised. One of the predisposing factors for seminoma is undescended testis which not only results in spermatogenic arrest but also in carcinoma in situ. This triad of abnormalities that is cryptorchidism, oligozoospermia and testicular cancer is known as testicular dysgenesis syndrome (TDS). Since there is an increased incidence of tumourogenesis in Down syndrome cases the cryptorchid condition may result in an increased risk for testicular carcinogenesis and its early onset and poor prognosis. Therefore all Down syndrome cases with cryptorchidism should be counselled to go in for surgical descent of testis at the earliest age and also to come for regular follow up for early detection for any foci of malignancy. This is the youngest testicular seminoma ever reported in human. This tumour occurred in a 2-year-old child and it is possible that Trisomy 21 may predispose to early onset of seminoma and such cases should be under regular follow up. Thus improved understanding and identification of various urogenital anomalies associated with Down syndrome will aid in better management of these cases. This case report and review of literature all suggest that Down syndrome is associated with an increased risk of development of seminoma and that too at an early age. This advocates a need for thorough gonadal examination in all cases of Down syndrome.

Body Temperature↗
PubMed2004

Yq microdeletions--azoospermia factor candidate genes and spermatogenic arrest.

In the last few years considerable progress has been made in the study of sperm physiology and the biology of gamete interaction, furthering our understanding of the pathophysiology of male infertility. With the advent of assisted reproductive technology and intracytoplasmic sperm injection, study of the various factors leading to spermatogenic impairment has become a major focus of scientific research. Understanding the genetic factors that lead to infertility has taken on a certain urgency, as we have learned not only of the transmission to male offspring of spermatogenic impairment, but that these offspring may also be born with a secondary, larger deletion with worsening of phenotype and genital ambiguity. Ten to twenty-five percent of couples encounter difficulty procreating. Microdeletions of the long arm of the Y chromosome are associated with spermatogenic failure and have been used to define three regions on Yq (AZFa, AZFb, and AZFc) that are critical for spermatogenesis. This study was conceived in order to identify the frequency of submicroscopic interstitial deletions in azoospermia factor loci in infertile Indian males. One hundred and seventy five males with nonobstructive oligozoospermia and azoospermia were included in this study. Semen analysis was done in each case to determine the spermatogenic status-normospermic, oligozoospermic (< 20 million sperm/mL), or azoospermic (no sperm in the semen). Detailed medical, clinical, reproductive, and family histories were taken of each patient. Thirty G-banded metaphases were analyzed in each case and polymerase chain reaction microdeletion analysis was done in 133 cytogenetically normal cases. For this genomic, DNA was extracted using peripheral blood. The sequence tagged site primers tested in each case were sY84, sY86 (AZFa); sY113, sY116, sY127, sY134 (AZFb); sY254, sY255 (AZFc). Polymerase chain reaction amplifications found to be negative were repeated at least three times to confirm the deletion of a given marker. The polymerase chain reaction products were analyzed on a 1.8% agarose gel. Eight of the 133 cases showed deletion of at least one of the sequence tagged site markers. Review of the literature has shown that the overall frequency of microdeletions varies from 1% to 55%. In the present study the frequency of microdeletion was 6.01%. Deletions were detected in cases with known and unknown etiology with bilateral severe testiculopathy.

Chromosome Aberrations↗
PubMed2003

Molecular screening for Yq microdeletion in men with idiopathic oligozoospermia and azoospermia.

Infertility affects 15% couples attempting pregnancy and in 40-50% of these cases the male partner has qualitative or quantitative abnormalities of sperm production. Microdeletions in the azoospermia factor (AZF) region on the long arm of the Y chromosome are known to be associated with spermatogenic failure and have been used to define three regions on Yq (AZFa, AZFb and AZFc) which are critical for spermatogenesis and are recurrently deleted in infertile males. Semen analysis was carried out on one hundred and twenty five infertile males with oligozoospermia and azoospermia. Cytogenetic analysis was done for all the cases and in all cytogenetically normal cases (n = 83) microdeletion analysis was carried out on DNA extracted from peripheral blood using PCR. The sequence tagged sites (STS) primers sY84, sY86 (AZFa); sY127, sY134 (AZFb); sY254, sY255 (AZFc) were used for each case. Eight of the eighty three cases (9.63%) showed deletion of at least one of the STS markers. Correlation of phenotype with microdeletion was done in each case to determine any phenotype association with deletion of particular AZF locus. Based on the present study, the frequency of microdeletion in the Indian population is 9.63%. This study emphasizes the need for PCR analysis for determining genetic aetiology in cases with idiopathic severe testiculopathy.

Adult↗
PubMed2002

Etiology, clinical profile, gender identity and long-term follow up of patients with ambiguous genitalia in India.

There is little information on the profile of children with ambiguous genitalia in India. Presented here is an analysis of patients with ambiguous genitalia registered in a general endocrine clinic during the last 2 decades. Seventy-four patients (age 4 months to 36 years) were registered during this period. Fifty-two were more than 5 years old at the time of registration. Thirty-five were reared as females, 29 as males; nine children (4 months to 1 year old) were brought for sex assignment, and one (with epispadias) was brought for correction of urinary incontinence. Investigations revealed 28 patients with congenital adrenal hyperplasia, 14 dysgenetic male pseudohermaphroditism, ten true hermaphroditism, six partial androgen insensitivity, four castration and one epispadias. There were eight patients with perineal hypospadias with normal Leydig cell reserve (normal LH, FSH and testosterone response to LHRH). Sex of rearing and gender identity were concordant in all except the patients with perineal hypospadias with normal Leydig cell response. These observations support the theory that prenatal androgen exposure masculinizes the brain.

Adolescent↗
PubMed2002

AZF microdeletions associated with idiopathic and non-idiopathic cases with cryptorchidism and varicocele.

AIM: To identify submicroscopic interstitial deletions in azoospermia factor (AZF) loci in idiopathic and non-idiopathic cases of male infertility in Indians. METHODS: One hundred and twenty two infertile males with oligozoospermia or azoospermia were included in this study. Semen analysis was done to determine the sperm density, i.e., normospermia (>20 million/mL), oligozoospermia (<20 million/mL) or azoospermia. They were subjected to detailed clinical examination and endocrinological and cytogenetic study. Thirty G-banded metaphases were analyzed in the 122 cases and polymerase chain reaction (PCR) microdeletion analysis was done in 70 cytogenetically normal subjects. For this genomic DNA was extracted using peripheral blood. The STS primers tested in each case were sY84, sY86 (AZFa); sY127, sY134 (AZFb); sY254, sY255 (AZFc). PCR amplifications found to be negative were repeated at least 3 times to confirm the deletion of a given marker. The PCR products were analyzed on a 1.8 % agarose gel. RESULTS: Eight of the 70 cases (11.4 %) showed deletion of at least one of the STS markers. Deletions were detected in cases with known and unknown aetiology with bilateral severe testiculopathy and also in cryptorchid and varicocele subjects. CONCLUSION: AZF microdeletions were seen in both idiopathic and non-idiopathic cases with cryptorchidism and varicocele. The finding of a genetic aetiology in infertile men with varicocele and cryptorchidism suggests the need for molecular screening in non-idiopathic cases.

Adult↗
PubMed2001

Prenatal diagnosis of chromosomal abnormalities in women with high risk pregnancies.

BACKGROUND & OBJECTIVES: Prenatal diagnosis helps in averting the birth of infants with chromosomal abnormalities. Fluorescence in situ hybridization (FISH) has been introduced as a potentially powerful tool in clinical cytogenetics. Several studies have reported successful prenatal diagnosis of chromosomal abnormalities in high risk pregnancies using FISH, however there are no reported studies from an Indian set up. Prenatal diagnosis for the detection of chromosomal abnormalities was carried out by conventional cytogenetics in the present study in the foetuses of high risk pregnancies in women attending a tertiary care facility in north India. These cases were further analyzed using FISH, to test the efficiency and utility of this technique for prenatal detection of common aneuploidies. METHODS: A total of 82 women with high risk pregnancies (81 singleton, 1 twin) were included in the study. Prenatal diagnosis was performed in these women using conventional chromosomal analysis (CCA) and interphase or metaphase FISH on chorionic villus or amniotic fluid or cord blood samples. RESULTS: Chromosomal analysis was successful in 80 instances and uninformative in 2. Abnormal karyotypes were detected in five (6.09%) of these women. FISH was successful in all the subjects and the results were in conformity to the cytogenetic results. In the 2 women where cytogenetic analysis was uninformative, results were given on the basis of interphase FISH. INTERPRETATION & CONCLUSION: The study clearly demonstrates that prenatal diagnosis is useful in the detection of chromosomal abnormalities in foetuses of women with high risk pregnancies. FISH is a powerful sensitive molecular cytogenetic technique, through which specific chromosomal abnormalities can be diagnosed/identified rapidly and accurately and may be used as an adjunct to conventional cytogenetic analysis.

Adult↗
PubMed2000

Parental age in Indian patients with sporadic hereditary retinoblastoma.

There is a consistent correlation between sporadic hereditary retinoblastoma and parental age. It has been proven beyond doubt that the birth rank is correlated with parental age. In the present study, a test for the effect of birth rank was performed in order to assess the risk of developing retinoblastoma with increased parental age. The study of the effect of birth rank showed a significant association between sporadic retinoblastoma (bilateral and unilateral) and late para, indicating that fresh germline mutations must have taken place in some of the sporadic cases. An investigation of the effect of birth rank on familial cases, obtained from published papers and our own series, showed that familial retinoblastoma is significantly associated with early para, suggesting early parental age. Further analysis of the mean paternal and maternal ages of sporadic cases (bilateral and unilateral) showed that the mean paternal age of sporadic bilateral (sporadic hereditary) cases was higher than that of sporadic unilateral cases (p<0.05). No such correlation was seen with mean maternal age. Thus, the present study shows that a high paternal age may be associated with sporadic bilateral (sporadic hereditary) retinoblastoma.

Adult↗
PubMed2000

Hernia uterus inguinale in a 46,XX female. A case report.

BACKGROUND: Hernia uterus inguinale, a rare congenital anomaly, is usually found in hermophrodites. CASE: A case of lateral fusion defect associated with müllerian duct development in a young woman with primary amenorrhea and normal karyotype occurred. In our patient, bilateral müllerian duct systems were rudimentary and failed to fuse in the midline. The left horn of the uterus and ipsilateral ovary lay in the left inguinal canal. The right horn of the uterus, along with the tube and ovary, was intraabdominal. CONCLUSION: In the operative management of this rare anomaly, care must be taken to preserve and reposition the ovary in the abdominal cavity.

Adult↗
PubMed1999

Nongonadal neoplasia in patients with Turner syndrome.

In a prospective study of 50 patients with retinoblastoma, a 10-year-old girl with unilateral (right eye) retinoblastoma was found to have 45,X karyotype. Because there is increasing evidence of nongonadal neoplasia occurring in patients with Turner syndrome in addition to the gonadal tumor from dysgenetic gonads, we reviewed the occurrence of nongonadal neoplasia in Turner syndrome cases. Of all the nongonadal neoplasia, neurogenic tumors show a preponderence among children and young adults with Turner syndrome. To the best of our knowledge, this is the first reported case of Turner syndrome with retinoblastoma. The available literature strongly suggests that patients with Turner syndrome may be at risk of developing neurogenic tumors. Further studies are necessary to identify the role of some X-linked genes that escape X-inactivation in tumorigenesis in patients with Turner syndrome.

Child↗
PubMed1998

Laparoscopic gonadectomy in male pseudohermaphrodites.

OBJECTIVE: To study patients of male pseudohermaphroditism and establish the laparoscopic approach for gonadectomy in these cases. STUDY DESIGN: Seven phenotypic females with XY karyotype were evaluated through a diagnostic protocol which included clinical, cytogenetic, hormonal, endoscopic and histologic evaluation. The gonads were then removed by laparoscopic surgery. RESULTS: The seven patients included three patients of pure gonadal dysgenesis, two patients of testicular feminization and one patient each of mixed gonadal dysgenesis and dysgenetic male pseudohermaphroditism. Two of the seven patients (28.57%) had gonadal neoplasias on histopathology-one dysgerminoma and one occult seminoma. In all of these patients, removal of the gonads was accomplished laparoscopically. No complications occurred during any of the surgeries. CONCLUSION: Due to the reduced morbidity, shorter hospital stay and safety, laparoscopic gonadectomy can be considered the treatment of choice for the removal of gonads in male pseudohermaphrodites in the hands of experienced laparoscopic surgeons.

Adolescent↗
PubMed1998

Mosaic partial trisomy of chromosome 5 (q33-q ter) associated with fetal polycystic kidneys.

A case of de novo mosaic partial trisomy of chromosome 5 (q33-q ter) in a stillborn male fetus with bilateral polycystic kidneys, and atrial septal defect, is reported. Fetal cord blood sampling was carried out at 25 weeks of gestation because of bilateral polycystic kidneys with severe oligohydramnios observed on ultrasound examination of the fetus. The family history was notable for the presence of similar phenotypic abnormality in the mother and sibling. However, no chromosomal abnormality was detected in other family members. Significance of this rare chromosomal abnormality and its association with congenital malformations in the fetus and in the family is being discussed.

Chromosomes, Human, Pair 5↗
PubMed1997

Absence of pericentromeric heterochromatin (9qh-) in a patient with bilateral retinoblastoma.

The polymorphisms of constitutive heterochromatin regions, present on chromosomes 1, 9, 16 and Y, are inherited in a Mendelian fashion. The C-band heteromorphism has been reported to be associated with various types of cancer. Heterochromatin is considered to play a role in protecting genome against the mutagens. Changes in the quantity and proportion of the different types of satellite DNA might increase the genetic susceptibility in people with heterochromatic variations, which in turn cause chromosome instability and predispose the individual to cancer. We report a case of bilateral retinoblastoma with complete absence of pericentromeric heterochromatin on one of the chromosomes number 9. A similar deficiency of pericentromeric heterochromatin on chromosome number 9 and 16 has been reported in a phenotypically normal individual and a Down syndrome case, respectively. This deficiency was found to be inherited from the father in all the three cases. Complete absence of pericentromeric heterochromatin of chromosome 9 is not being reported in association with cancer syndromes. Further studies are necessary to understand the role of this factor in normals and in those with cancer susceptibility, specially with retinoblastoma and the paternal origin of this deficiency.

Chromosome Deletion↗
PubMed1997

Balanced X; 22 translocation in a patient with premature ovarian failure.

A case of balanced X; autosome translocation 46, X, t (X; 22) (q 24; q 13) in a 25-year-old female with secondary amenorrhea and premature ovarian failure (POF) is described. The relationship between balanced X; autosome translocation [t (X; A)] and varied phenotypic expression observed in these women is discussed. This case highlights the importance of early recognition of these women in order to give them the best chance of conception in their oligohypomenorrhic phase before complete loss of gonadal function.

Adult↗
PubMed1997

Lymphoid blast crisis during complete cytogenetic remission following interferon-alpha and hydroxyurea therapy.

Chronic myelogenous leukemia (CML) is a clonal disorder starting with a chronic phase and progressing to an acute blastic phase. Philadelphia (Ph) chromosome formation results in the relocation of the ABL oncogene from the chromosome 9q34 to BCR region on 22q11, forming the BCR/ABL fusion gene. The Ph chromosome once detected rarely disappears, except as a result of therapy. We present an unusual Ph-positive CML case, which developed lymphoid blast crisis in complete cytogenetic remission following interferon-alpha and hydroxyurea therapy. Sequential cytogenetic investigations were carried out on bone marrow. After a standard Ph translocation seen at diagnosis, from the 8th month of therapy all metaphases showed a normal diploid karyotype. Fluorescence in situ hybridization detected residual BCR/ABL-positive interphase cells during the 12th month of therapy. In the 14th month, the patient showed 27% blasts in marrow though normal cytogenetics was maintained. Present findings suggest blastic transformation occurred in a Ph-negative lymphoid clone. This supports the hypothesis that an actual leukemogenic event occurs in a multipotent stem cell prior to the acquisition of Ph translocation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Clinical and DNA studies on 46, XY females with gonadal dysgenesis. A report of six cases.

BACKGROUND: Understanding the process of sex determination has been aided by the molecular analysis of individuals whose karyotype does not correspond to their phenotype, 46, XX males and 46, XY females. CASES: We studied the clinical and molecular data on six 46, XY females of Indian ethnic origin. In each subject, cytogenetic analysis indicated a 46, XY karyotype without mosaicism. In four of the cases DNA studies were performed on the sex-determining region, Y chromosome gene. A de novo point mutation was identified in one subject. CONCLUSION: Our data provide additional evidence for genetic heterogeneity in the etiology of 46, XY gonadal dysgenesis.

Adolescent↗
PubMed1994

Genetic heterogeneity in true hermaphrodites. A report of two cases.

True hermaphrodites are identified from the presence of ambiguous genitalia with both ovarian and testicular tissue. Two cases presented below had a 46,XX chromosome pattern, cryptorchidism and undescended testes. Both cases showed an absence of secondary sexual characteristics and presence of bilateral breasts and a uterus. The gonads in case 1 were an ovotestis and testis (left side) and in case 2 were an ovary and testis (right side). Case 1 was analyzed for a sex-determining region on the Y chromosome (SRY) and was negative. Phenotypic, gonadal and molecular studies suggest that 46,XX true hermaphroditism is a genetically heterogeneous condition.

Adolescent↗