Biomedical subjects

V Malan

Publications and source records attributed to V Malan.

4 recordsLinked to original sources

PubMed2007

The long-term followup of 33 cases of true hermaphroditism: a 40-year experience with conservative gonadal surgery.

PURPOSE: Little is known about long-term outcomes of conservative gonadal surgery in true hermaphroditism. We present our experience with evaluation and treatment of a large series of children with this rare form of ambiguous genitalia, focusing on gonadal structure and function before and after conservative gonadal surgery. MATERIALS AND METHODS: We retrospectively reviewed 33 consecutive patients with histologically confirmed true hermaphroditism treated at the Hopital des Enfants-Malades between 1965 and 2005. RESULTS: The most common karyotype of true hermaphrodites was 46,XX, constituting 82% of our series. The frequency of finding the SRY gene in 46,XX cases was 35%. Ovotestis was the most frequent finding (65%) and testis the rarest (9%). Ovarian tissue was more often found on the left side, and testicular tissue on the right side (p <0.05). Proper gonadal tissue was preserved in 28 cases. No gonadal tumors were detected during followup. Ovarian tissue remained normal, while testicular tissue gradually developed signs of dysgenesis in all biopsied cases, confirmed by endocrinological studies. However, testosterone production remained satisfactory in the majority of cases during followup. CONCLUSIONS: Diagnosis of true hermaphroditism is well defined and the condition can be recognized even prenatally. Conservative gonadal surgery is the procedure of choice after a diagnosis of true hermaphroditism. Continued followup is necessary because of the multiple psychological, gynecological and urological problems encountered postpubertally by these patients.

Child↗

PubMed2006

Chromosome segregation in an infertile man carrying a unique pericentric inversion, inv(21)(p12q22.3), analysed using fluorescence in situ hybridization on sperm nuclei: significance for clinical genetics. A case report.

We report the case of a 40-year-old patient referred to our centre after 3 years of infertility. Karyotyping with the aid of fluorescence in situ hybridization (FISH) analysis showed a unique pericentric inversion of chromosome 21:46,XY,inv(21)(p12q22.3). This type of intrachromosomal structural rearrangement can lead to chromosome imbalance in offspring by producing unbalanced gametes if an odd number of crossover events occur within the inverted segment. Therefore, partial trisomy/monosomy with clinical consequences can be observed in the progeny of carriers. Semen samples from the inversion carrier were analysed by FISH using a combination of probes [a subtelomeric 21q probe and a locus-specific Down's syndrome critical region (DSCR) probe] to evaluate the proportion of recombinant chromosomes. Sperm-FISH analysis of 3400 spermatozoa revealed a 67.4% rate of balanced chromosomes (normal or inverted). The frequencies of recombinant chromosomes with duplication of the long arm and deletion of the short arm, and vice versa, were 11.2 and 21.4%, respectively. The risk for the couple of conceiving a child with an unbalanced chromosome 21 is estimated to be around 32%. This case study shows the utility of sperm-FISH analysis in the genetic counselling of a pericentric inversion in a male carrier to assess the frequency of recombinant chromosomes and therefore evaluate the probability of having a normal conception.

Adult↗

PubMed2006

Chimera and other fertilization errors.

The finding of a mixture of 46,XX and 46,XY cells in an individual has been rarely reported in literature. It usually results in individuals with ambiguous genitalia. Approximately 10% of true human hermaphrodites show this type of karyotype. However, the underlying mechanisms are poorly understood. It may be the result of mosaicism or chimerism. By definition, a chimera is produced by the fusion of two different zygotes in a single embryo, while a mosaic contains genetically different cells issued from a single zygote. Several mechanisms are involved in the production of chimera. Stricto sensu, chimerism occurs from the post-zygotic fusion of two distinct embryos leading to a tetragametic chimera. In addition, there are other entities, which are also referred to as chimera: parthenogenetic chimera and chimera resulting from fertilization of the second polar body. Furthermore, a particular type of chimera called 'androgenetic chimera' recently described in fetuses with placental mesenchymal dysplasia and in rare patients with Beckwith-Wiedemann syndrome is discussed. Strategies to study mechanisms leading to the production of chimera and mosaics are also proposed.

Chimera↗

PubMed2004

A new case of a severe clinical phenotype of the cat-eye syndrome.

A new case of severe clinical phenotype of the cat-eye syndrome: We report on a female infant with severe clinical phenotype of Cat-Eye Syndrome (CES). At birth, she had respiratory distress and marked hypotonia. Physical examination showed major craniofacial anomalies including microcephaly, bilateral total absence of the external ears, hypertelorism, bilateral ocular coloboma of iris and micrognathia. In addition, she had anal stenosis, a patent ductus arteriosus and intra- and extra- hepatic biliary atresia. She deteriorated with the development of bradycardia. She died at age one month of cardiac failure. Cytogenetic analysis of the proband showed an extra de novo small bisatelllited marker chromosome in all cells examined. Molecular cytogenetic analysis with fluorescence in situ hybridization (FISH) identified the marker as a CES chromosome. Thus, the patient's karyotype was: 47, XX, +idic(22)(pter-->q11.2 ::q11.2-->pter). The duplication breakpoints giving rise to the CES chromosome were distal to the DiGeorge Syndrome (DGS) locus 22q11.2. The marker could be classed as a type 11 symmetrical (10). According to a recent review of CES literature (1) only 41 % of the CES patients have the combination of iris coloboma, anal anomalies and preauricular anomalies. Almost 60% are hard to recognize by their phenotype alone. Only twelve patients showed a severe clinical phenotype leading to the death of the child. This phenotypic variability increases the difficulties of genetic counseling.

Anal Canal↗