Effect of paternal age on human sperm chromosomes.

OBJECTIVE: To investigate whether increased age alters the frequency and type of chromosomal anomalies in human spermatozoa. DESIGN: Semen specimens were collected from donors via masturbation; cytogenetic studies were performed on sperm chromosomes after heterologous (human-hamster) in vitro fertilization. SETTING: Cytogenetics Laboratory, Genetics Department, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil. PATIENT(S): Seven men ages 59-74 (older group) and five men ages 23-39 (control group). MAIN OUTCOME MEASURE(S): Frequency and types of chromosomal anomalies in older and control group donors. RESULT(S): The frequency of numerical and structural aberrations (acentric fragments and complex radial figures) was significantly greater in chromosomes of older donors when compared with those of the control group. CONCLUSION(S): The higher frequency of sperm chromosome aberrations in older men was mainly a result of increased nondisjunction, acentric fragments, and complex radial figures.

Phylloid pattern of pigmentary disturbance in a case of complex mosaicism.

Among the various types of pigmentary disturbances associated with mosaicism, the phylloid pattern (Greek phyllon = leaf, eidos = form) is characterized by multiple leaf-like patches reminiscent of an art nouveau painting. The number of cases displaying this unusual pattern is so far limited. We describe a phylloid pattern of hypomelanosis in a 3-year-old girl with multiple congenital anomalies including microcephaly, midfacial hypoplasia, cleft lip, coloboma, posteriorly rotated ears, pectus carinatum, and pronounced mental and physical retardation. In addition, this child had oval or oblong patches of hyperpigmentation involving the trunk in a horizontal arrangement dissimilar from the phylloid hypomelanotic pattern. In peripheral blood lymphocytes a karyotype 46,XX,-13,+t(13q;13q) was consistently found, whereas cultured skin fibroblasts showed a complex form of mosaicism comprising three different abnormal cell lines (46,XX,-13,+t(13q;13q)/45,XX,-13/45,XX,-13,+frag). This case provides further evidence that the phylloid pattern represents a separate category of pigmentary disturbance to be distinguished from other types of cutaneous mosaicism such as the lines of Blaschko or the checkerboard arrangement.

Syndrome of psychomotor retardation, bulbous nose, and epilepsy (Hernandez syndrome): a Brazilian case.

A new case of Hernandez syndrome is described in a 16-year-old Brazilian girl. The syndrome consists mainly of psychomotor retardation, epilepsy, a bulbous nose and obesity.

Fragile X syndrome. Clinical and cytogenetic studies.

Three families with the fragile X syndrome were studied with the aim to establish the most frequent clinical signs in the affected individuals and heterozygous women. The clinical evaluation, IQ level measurements and cytogenetic studies were performed in 40 subjects, 20 males and 20 females. The fragile X diagnosis was confirmed in all the male individuals with mental retardation. In the postpubertal subjects the most frequent clinical signs were inner canthal distance < 3.5 cm, macro-orchidism, long and narrow face and high arched palate while in the prepubertal subjects the behavioral characteristics as hyperactivity and poor eye contact were the most frequent and were observed in all patients. Twenty six percent of the heterozygous women presented with mental retardation and showed clinical signs rather than behavioral ones. All male individuals with mental retardation were observed as having fragile X [fra(X)] in lymphocytes culture. Sixty three percent of women showed fra(X). There was a positive correlation between the frequency of fra(X) and the clinical characteristics. We emphasize the importance of the clinical evaluation in the study of familial mental retardation and in the screening of isolated cases with suspect of having the fragile X syndrome.

Three new cases of spondylocarpotarsal synostosis syndrome: clinical and radiographic studies.

Spondylocarpotarsal synostosis syndrome (SSS) or congenital synspondylism is a recently delineated clinical entity. At least 15 patients have been reported. We present 3 new patients, 2 of whom were sibs born to first-cousin parents. All of our patients had multiple synostoses involving cervical, thoracic and/or lumbar vertebral bodies and carpal/tarsal bones, scoliosis/lordosis, and short stature. Sensorineural deafness was found in 2 of the 3 patients. Analysis of clinical manifestations suggests clinical variability and genetic heterogeneity in SSS. Of a total of 18 SSS patients, 10 were five pairs of sibs from five families, with first-cousin consanguinity of parents in 3, indicating that at least one type of SS is an autosomal-recessive disorder.

Retinal changes and tumorigenesis in Ramon syndrome: follow-up of a Brazilian family.

We report on the clinical evolution of the Brazilian family with Ramon syndrome described by de Pina-Neto et al. [1986, Am J Med Genet 25:441-443]. Three members (patients IV-2, IV-18, and IV-19) have developed pigmentary changes in the retina and paleness of the optic disk. Patient IV-18 also has developed giant hypertrophy of the labia minora that, when examined histopathologically, was found to be due to neoplastic fibroblast and epithelial proliferation caused by a fibromatous process similar to that reported in the gingivae of the patients with this syndrome. Audiologic function of patient IV-2 was normal, and no skin lesions were detected. The articular signs and symptoms show that the affected relatives developed rheumatoid arthritis, which is currently inactive in patient IV-18, whereas patient IV-2 did not develop these alterations.

Clinical-neurologic, cytogenetic and molecular aspects of the Prader-Willi and Angelman syndromes.

The Prader-Willi syndrome (PWS) and the Angelman syndrome (AS) are human neurogenetic disorders involving the imprinting mechanism, at the 15q11-13 chromosome region. The predominant genetic defects in PW are 15q11-13 deletions of paternal origin and maternal chromosome 15 uniparental disomy. In contrast, maternal deletions and paternal chromosome 15 uniparental disomy are associated with a different neurogenetic disorder, the AS. In both disorders, these mutations are associated with parent-of-origin specific methylation at several 15q11-13 loci. We studied 5 patients suspect of PWS and 4 patients suspect of AS who were referred to the Medical Genetics Unit at the University Hospital of Medical School from Ribeirão Preto. Our objective was to establish the correct clinical and etiological diagnosis in these cases. We used conventional cytogenetics, methylation analysis with the probe KB17 (CpG island of the SNRPN gene) by Southern blotting after digestion with the Xba I and Not I restriction enzymes. We studied in patients and their parents the segregation of the (CA)*** repeats polymorphisms by PCR, using the primers 196 and IR4-3R. All the patients had normal conventional cytogenetical analysis. We confirmed 3 cases of PWS: one by de novo deletion, one by maternal chromosome 15 uniparental disomy and one case with no defined cause determined by the used primers. We confirmed 2 cases of AS, caused by de novo deletion at the 15q11-13 region, and one case with normal molecular analysis but with strong clinical characteristics.

Tetrasomy 9p caused by idic (9) (pter----q13----pter).

Cytogenetic investigation on a malformed male infant showed an extra chromosome similar to chromosome 9 in all metaphases studied. GTG, CBG, and G-11 staining suggested that the extra chromosome was an abnormal 9, permitting the identification of the chromosome constitution as 47,XY,+idic (9) (pter----q13----pter).

Partial 3p trisomy and different rearrangements involving chromosome 3 in the proposita's family.

A case of partial 3p trisomy is reported here. A review of published cases (8 males, 2 females, 7 families) shows a characteristic pattern of anomalies, constituting one more syndrome of multiple congenital anomaly and mental retardation (MCA/MR) characterized by microcephaly, brachycephaly, frontal bossing, temporal identation, square hypertelorism or telecanthus, epicanthus, short nose with a large tip, prominent cheeks, long and protruding philtrum, large and downturned mouth, protruding mid-upper lip, micro- or retrognathia, short neck, congenital heart defects, gastrointestinal malformation, penile hypoplasia, neuromotor or mental retardation, and predominance of whorls on digits. The proposita had a 46,XX,der(11),t(3;11)(p21;q25) karyotype. The mother was carrier of a de novo 3;11 balanced translocation. Chromosome mosaicism was detected in a female sibling of the proposita: 46% of her cells were 46,XX and 54% had 46,22,t(3;20(p21;13) karyotype - ie, a de novo 3;20 balanced translocation. We discuss the origin of this mosaicism and the possible meaning of the breaks involving the same region of chromosome 3 (region 3p 21) in the members of the proposita's family.