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Biomedical subjects

G S Gericke

Publications and source records attributed to G S Gericke.

At least 37 records · Page 2Linked to original sources
PubMed1995

Congenital anomalies in rural black South African neonates--a silent epidemic?

STUDY OBJECTIVE: To ascertain the incidence and spectrum of congenital anomalies in neonates born in a rural hospital. DESIGN: This was a prospective, hospital-based study, undertaken on liveborn neonates over the period 12 June 1989 - 31 December 1992. SETTING: Mankweng Hospital, Sovenga, Northern Transvaal. MAIN RESULTS: Of a total of 10,380 neonates born during this period, 7,617 (73.4%) were examined within the first 24 hours of life. On the basis of published observations, only 26.2% of severe congenital anomalies diagnosable by age 5 years are diagnosable at birth. In this South African study the finding at birth of severe, externally visible congenital anomalies in 14.97 per 1,000 livebirths could mean that by age 5 years the minimum cumulative incidence of severe congenital anomalies may involve 57.14 per 1,000 children. Extrapolating from other Third-World studies, the cumulative incidence of severe congenital anomalies in such communities may affect up to 84.85 per 1,000 children by the age of 5 years. High incidences of neural tube defects (3.55 per 1,000 livebirths) and Down syndrome (2.10 per 1,000 livebirths), both conditions which can be prevented by prenatal screening, were recorded. CONCLUSIONS: These figures indicate the necessity for inclusion of appropriate prenatal, genetic, family planning and paediatric facilities into the primary health care delivery system of rural areas, to manage such problems and to initiate programmes to reduce the incidence of selected congenital anomalies such as Down syndrome and neural tube defects.

Abnormalities, Multiple↗
PubMed1994

Acrocallosal syndrome in two African brothers born to consanguineous parents.

We describe two mentally retarded brothers with craniofacial anomalies, polydactyly, and other clinical manifestations compatible with the acrocallosal syndrome (ACS). These are the first black patients from Africa with this diagnosis. They are also the fourth set of sibs described with ACS, and together with the parental consanguinity documented in this family, confirm autosomal recessive inheritance of this syndrome. The clinical manifestations in our patients confirm the intrafamilial variability of the syndrome. Postnatal onset of growth retardation is proposed as an additional manifestation of ACS.

Abnormalities, Multiple↗
PubMed1990

An association between certain congenital abnormalities and the malignant hyperthermia trait.

Although an association between malignant hyperthermia (MH) and congenital abnormalities has been recorded, no prospective study has been attempted to investigate this relationship. Standardised in vitro muscle tests were performed, because of impending anaesthesia for corrective surgery, on 25 children with birth defects similar to those induced by hyperthermia in laboratory animals, and in whom excessive pyrexial reactivity to anaesthesia, drugs or stress were recorded. Fifteen of the 25 children were MH positive by responding abnormally to the administration of halothane/caffeine. Five of these patients reacted positively to both caffeine and halothane, while the remainder manifested a contractile response to halothane only. This study underlines the existence of an anaesthetic risk factor associated with certain congenital abnormalities and neurodevelopmental delay and emphasises the need for further research to elucidate the possible importance of heat stress during fetal development in genetically susceptible individuals.

Adolescent↗
PubMed1990

The role of human genetics in society: implications for legal involvement.

The tools and techniques of human genetics are very much part of medicine in the 1990s and beyond. Man's motivation for self improvement has been an integral part of his make-up since time immemorial. The human desire for preserving the fittest and weeding out the worst remains the same since stone-age man practised castration, coitus interruptus, mechanical contraception, urethral surgery, abortion, infanticide, infant cannibalism, delayed lactation and geronticide. During the intervening centuries there have been scores of attempts to develop dream states; at forced mass migration, or to protect social order by casting out the unwanted under various guises. For the first time we are catching a glimpse of the possibility of significantly altering our genetic constitution, supplying us with the tools to realize very deep seated instincts, but without adequate knowledge of all the dangers. It is foreseen that the law has an important contribution in maintaining the balance between seemingly conflicting interests of the individual, the community, the state and genetic research scientists. There is a need for pro-active involvement in the author's opinion.

Eugenics↗
PubMed1989

Does heat damage fetuses?

Temperature affects phenotypic variation during critical developmental stages in all forms of life that have been studied thus far. In animal studies of heat teratogenicity, adverse effects have ranged from disruption of the normal cell cycle leading to decreased numbers of cells, to the induction of developmental abnormalities by means of embryonic cell death. The heat shock response is a universal cellular stress reaction in which the transcriptional and translational mechanisms of the cell are pre-empted by preferential induction of heat shock protein synthesis. Occurrence of such a phenomenon during prenatal life could lead to the absence of essential gene products at critical stages of development. The crucial question of whether temperature induced cellular and genetic effects ever occur during human fetal development has been considered only in relation to maternal hyperthermia, which is generally viewed as not being of significance in human teratology. We propose that teratogenicity may result from fetal hyperthermia unrelated to maternal hyperthermia, caused either by impaired fetomaternal heat dissipation due to reduced placental blood flow (extrinsic fetal hyperthermia) or by increased fetal heat production during hypermetabolic states (intrinsic fetal hyperthermia). The need for further studies in this regard is emphasized.

Animals↗
PubMed1986

Genetic and teratological considerations in the analysis of concordant and discordant abnormalities in twins.

Results from monozygotic (MZ) and dizygotic (DZ) twin research are often used in an attempt to gain a clearer understanding of the 'nature v. nurture' dilemma. Discordance between MZ twins has been considered to be environmental, and greater concordance in MZ compared with DZ pairs to be genetic. Current genetic and teratological theories considerably complicate the interpretation of concordance and discordance of abnormalities. The high rate of discordant intra-uterine death recently demonstrated in twins may profoundly influence the value of epidemiological studies usually performed in later life. Furthermore, indirect zygosity estimations based on sex ratios in DZ twins may be flawed because it is now recognized that increasing numbers of conditions are genetically heterogeneous. Emphasis is laid on problems of interpretation of discordance and concordance for developmental abnormalities in twins, and some possible mechanisms for their induction are discussed. Basic genetic concepts relevant to the expression of abnormalities in twins are outlined.

Cleavage Stage, Ovum↗
PubMed1984

Asymmetrical limb reduction deformities--aetiological considerations.

The clinical features of a newborn female infant with reduction deformities of three limbs and no additional major malformations are presented. Diagnostic precision is crucial for accurate prognostication since both genetic and non-genetic causes have to be considered in such instances. The main differential diagnosis in our patient included a number of specific inherited disorders of which limb reduction is a component, as well as the consequences of both early amniotic rupture and fetal vascular disruption. We favoured the latter and concluded that the risk of recurrence was minimal. The approach to limb reduction disorders should be individualized.

Abnormalities, Multiple↗
PubMed1984

Diagnostic considerations in arthrogryposis syndromes in South Africa.

Congenital rigidity of multiple joints poses a difficult diagnostic and therapeutic problem. There are also semantic difficulties as the non-specific term "arthrogryposis" is often used for any individual with congenital limitation of joint movement. Many distinct syndromes present in this way and as they differ in their course, prognosis and genetic implications, diagnostic precision is crucial. A diagnostic analysis is given of 247 South African patients in whom "arthrogryposis" had been recorded, and the pathogenesis and nosology of congenital contractures are discussed in this paper. Three of these stiff joint conditions were originally described in South African patients, i.e. Liebenberg synostosis syndrome, digitotalar dysmorphism, and the Gordon syndrome of autosomal dominant cleft palate, camptodactyly and club feet.

Arthrogryposis↗
PubMed1981

A marker X chromosome associated with nonspecific male mental retardation. The first South African cases.

This report describes the first cases of X-linked mental retardation with a marker X chromosome seen in South Africa, and forms part of an ongoing study. The marker was found in 11 affected males and 1 carrier female in 4 families investigated. The demonstration of the marker X chromosome characterized by a fragile site at the long arm (fra(X) (q27) in association with nonspecific X-linked mental retardation heralds a new era in cytogenetics. The attention of human geneticists everywhere is focused on various aspects of this fascinating phenomenon. It has now become possible to diagnose an apparently common familial cytogenetic condition with a high risk of recurrence and to identify female carriers; perhaps in time we will be able to provide prenatal diagnosis. Because of the familial involvement through X-linked inheritance the syndrome is believed to be more common than trisomy 21. The nature of the association of mental retardation with the marker X chromosome is unknown, but it could be related to close linkage with abnormal gene(s) or due to faulty transcription of the genes beyond the fragile site.

Adult↗