Investigação clínica e genética em meninas com baixa estatura idiopática

Chromosomal abnormalities detected by karyotyping among patients with secondary amenorrhea: a retrospective study

BACKGROUND

Chromosomal abnormalities (CAs) have been described in patients with secondary amenorrhea (SA). However, studies on this association are scarce.

OBJECTIVES

To evaluate the frequency and types of CAs detected by karyotyping in patients with SA.

DESIGN AND SETTING

This retrospective study was performed in a reference clinical genetic service in South Brazil.

METHODS

Data were obtained from the medical records of patients with SA who were evaluated between 1975 and 2022. Fisher's bicaudate exact test and Student's t-test were used, and P < 0.05 was considered significant.

RESULTS

Among 43 patients with SA, 14 (32.6%) had CAs, namely del (Xq) (n = 3), 45,X (n = 2), 46,X,r(X)/45,X (n = 2), 46,XX/45,X (n = 1), 46,X,i(q10)/45,X (n = 1), 47,XXX (n = 1), 46,XX/47,XXX (n = 1), 46,XX/47,XX,+mar (n = 1), 45,XX,trob(13;14)(q10;q10)/46,XXX,trob(13;14)(q10;q10) (n = 1), and 46,XX,t(2;21)(q23;q11.2) (n = 1). Additional findings were observed mostly among patients with CA compared with those without CA (P = 0.0021). No difference in the mean age was observed between the patients with SA with or without CAs (P = 0.268025).

CONCLUSIONS

CAs are common among patients with SA, especially those with short stature and additional findings. They are predominantly structural, involve the X chromosome in a mosaic, and are compatible with the Turner syndrome. Patients with SA, even if isolated, may have CAs, particularly del (Xq) and triple X.

A case of premature ovarian failure in a 33-year-old woman

Objective. To assess aetiology of a POF in a 33-year-old woman and, if possible, plan a cure. Design. Case report. Setting. medical genetics diagnostic unit in a university hospital. Patient. A 33-year-old woman with premature ovarian failure (POF). Intervention(s). Genetic counseling, karyotyping, FISH study. Result(s). Turner-like diagnosis. Conclusion(s). Most cases of POF remain idiopathic. Turner syndrome can occur in very different phenotypes; cytogenetic and molecular profiling can provide a definitive diagnosis in cases with nonclassical phenotype.

The role of the SHOX gene in the pathophysiology of Turner syndrome

Turner syndrome (TS) affects 1:2500 live females. It is caused by partial or complete absence of a sex chromosome. Patients with deletions of the distal segment of the short arm of X chromosome (Xp-) including haploinsufficiency of the SHOX (short stature homeobox) have, more often, short stature, skeletal abnormalities and hearing impairments. This article evaluates the current knowledge of the SHOX gene role in TS pathophysiology. Articles were searched from MEDLINE and LILACS databases, in the past 10 years, using the following keywords: Turner syndrome, SHOX gene, haploinsufficiency, short stature and hearing loss. As the inheritance of only one copy of the SHOX gene does not explain most of TS anomalies, more studies are needed to explain them. These studies will also improve understanding how SHOX participates in cartilage and bone growth and will help develop novel therapeutic strategies focused on SHOX-related disorders.

Diagnóstico da Síndrome de Turner: a experiência do Instituto Estadual de Diabetes e Endocrinologia - Rio de Janeiro, de 1970 a 2008

OBJETIVOS: descrever a experiência no diagnóstico da Síndrome de Turner (ST), focalizando a distribuição dos cromossomos, a idade, os sinais e sintomas característicos, conforme as fases da vida (lactância, infância, adolescência e adulta). MÉTODOS: estudo descritivo com 178 pacientes, atendidos de 1970 até 2008. Para análise estatística das diferenças percentuais usou-se o Epi-Info-2000 e para as diferenças entre as médias de idades o teste t de Student e o ANOVA. RESULTADOS: os cariótipos encontrados foram: 79 com 45,X (35,4%), 36 com isocromossomo Xq (20,2%) e 63 com outros mosaicos (35,4%). A média de idade do diagnóstico foi de 12,6 anos, sendo menor naquelas com 45,X. Tiveram o diagnóstico feito na lactância 11,3% das pacientes, 25,3% na infância, 51,1% na adolescência e 12,4% na fase adulta. Daquelas diagnosticadas antes dos cinco anos de idade, 70,6% apresentaram 45,X. Os sinais que levaram à suspeita diagnóstica na lactância foram o pescoço alado e o linfedema congênito de pés/mãos associados às dismorfias típicas; na infância e adolescência foi a baixa estatura. Cubitus valgus foi encontrado em 72,5% das pacientes e orelhas anômalas em 65% das pacientes diagnosticadas com menos de um ano de idade. CONCLUSÃO: o diagnóstico da ST é desnecessariamente atrasado, levando-se em consideração que algumas características típicas podem já estar presentes desde o nascimento.