Biomedical subjects
Publications and source records attributed to H Dar.
Ninety-seven healthy newborns with a Sydney line in 143 palms were re-examined between the ages of 10 and 14 months. The Sydney line was no longer present at follow-up in 58.8 per cent of these infants and in 66.4 per cent of the palms. It appears that the Sydney line, unlike the simian line and its variants, is age-dependent and is not a permanent structure of early intrauterine origin.
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A one year old female infant with mental and motor retardation and bilateral optic atrophy in association with pericentric inversion of chromosome No. 2 is described.
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Dermatoglyphic studies were carried out of 131 mothers and 95 fathers of children with Down syndrome and 200 controls (100 males and 100 females) using the Hopkins single score method. Twelve percent of the mothers and 2% of the fathers showed dermatoglyphic abnormalities including a distal axial triradius (t"), hypothenar ulnar loops, radial loops on digits IV and V and abnormal palmar creases, resulting in a positive Hopkins score or a score in the "overlapping range" (greater than -3). The origin of the extra chromosome could be determined in 23 of a total group of 40 families. In 22 of the former, the mother was the donor of the extra chromosome; in one it was the father, In these 23 families, a Hopkins score in the overlapping range was found in three mothers who were all under the age of 35 years at the birth of the affected child. Since cytogenetic studies cannot easily differentiate between meiotic nondisjunction and mosaicism as a basis for 21 trisomy in the progeny, it is possible that mothers with positive overlapping Hopkins scores represent undetected mosaics for a trisomic cell line. The dual approach utilizing dermatoglyphic and cytogenetic studies may aid in identifying persons with an enhanced risk for having children with Down syndrome.
A 22;22 Robertsonian translocation was diagnosed in a husband whose wife had had six consecutive early spontaneous abortions and no normal progeny. With the new multiple-exposure photography (MEP) technique, an accurate, objective and documentary sperm analysis was performed. No abnormality of the essentially defective, genetically unbalanced sperms could be detected in regard to sperm count, motility, velocity and morphology. The only similar translocation previously reported in a male was associated with azoospermia. Recent literature correlating chromosomal aberrations and reproductive failure in the male is discussed in relation to the reported case. The importance of including the male partner in the cytogenetic investigation of couples with habitual abortion is stressed.
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Consanguinity analysis of heterogeneous populations was performed on a group of 82 Israeli Jewish families with congenitally deaf probands, including 37 multiplex families with normal parents, 10 multiplex families with deaf parents, and 35 simplex families with deafness of unknown cause. Representative gene frequency was estimated as .0198, with two to four major gene loci per ethnic group. In both the simplex families and those with deaf parents, the only significant etiology found was homozygosity for pathologic recessive genes. Comparison of these findings in Israeli isolates with those in panmictic populations seems to imply that the genetic loci are not identical in the various isolates.
A dermatoglyphic and palmar crease analysis was carried out in 100 children aged six months to five years with psychomotor retardation (excluding Down's syndrome). When compared with 121 of the parents and a random group of 168 school-children, certain unusual features were found to be twice as common in the retarded children, demonstrating that these features may indicate an 'at risk' infant if found during routine examination of the newborn.
A prospective study was carried out to discern the outcome of pregnancy and distribution of birth weights of infants delivered of 85 women with sickle cell trait (AS) compared with a control group of 85 women with normal hemoglobin (AA) who were matched for race, age, parity, and sex of offspring. The distribution of birth weight of offspring of primiparous and multiparous women and the proportion of low-birth-weight infants did not differ significantly between infants born to mothers with AS and those in the control group. Similarly, there was no statistically significant difference between the birth weight of infants born to primipara or multipara. Also, the overall incidence of complications among women with AS did not differ from the incidence in the control group. The findings do not support previous reports that there may be definable pathologic correlates of childbearing in women with AS.
An analysis of palmar crease variants was carried out in a group of "at risk" newborns, without any evident congenital anomalies. This group consisted of 108 prematures, 74 infants who were small for gestational age, 62 newborns with history of gestational complications, and 46 newborns with a history of intrauterine methadone exposure. A system of classification was developed based on observations of 500 normal newborns as control subjects, 466 normal mothers, and 200 normal children. The palmar crease variants can be divided into four main groups, schematically presented as normal variants, simian crease and its variants, Sydney line and its variants, and another group of unusual variants which do not fit into the other groups. A study of these groups revealed that familial components, race, sex, and age are factors that can influence the expression of palmar crease patterns. There is an increased frequency of abnormal creases in each of the groups of "at risk" newborns. Moreover, there is an apparent association of interrupted transrerse creases and intrauterine methadone exposure.
Cytogenetic studies were performed on 57 families with pregnancy wastage (eg, two or more spontaneous abortions or stillbirths). Chromosomal abnormalities were ascertained in 17 couples, through offspring with congenital malformations. Seven families had children with neural tube defects, and five families also had a previous child with Down syndrome. One mother had mosaic Turner syndrome; two additional mothers and one father had balanced chromosome translocations. These findings indicate that chromosome analyses should be performed on every couple with repeated miscarriages or malformed children, and subsequent pregnancies at risk should be monitored by amniocentesis.
A pair of monozygotic, adolescent twins is discordant for sex. The phenotypic female twin has chromosome constitution of 46, XY/45, X. She displays many signs of Turner's syndrome, including typical facies, webbed neck, malformed left kidney, high plasma gonadotropins, and streak ovaries. However, her height is 154 cm which exceeds the height usually reported in Turner's syndrome. The male twin has a karyotype of 46, XY and normal sexual development. Only two other reports of pairs of monozygotic twins of opposite sex have been published.
As the variability and possible clinical significance of palm increase abnormalities receive greater attention, an accurate and objective method for evaluating the palm increase variants is required. A new method is described employing a topographic approach. A network of co-ordinates drawn on the palm prints enables an accurate and reproducible description to be made of unlimited numbers of variants of palm crease configurations. This method makes possible quantitative studies rather than merely qualitative descriptions of the palm crease patterns. To determine its usefulness, this method was employed in a comparative study of 100 individuals with Down's syndrome and 100 controls. Significantly higher total degree of transversality (T-DoT), as defined in this paper, was found in the Down's syndrome group. T-DoT may be a useful parameter in the evaluation of crease patterns of patients with congenital and genetic disorders.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.