Mol Genet Metab. 2010 Oct 20. [Epub ahead of print]
http://www.ncbi.nlm.nih.gov/pubmed/21059483
The GALT rush: High carrier frequency of an unusual deletion mutation of the GALT gene in the Ashkenazi population.
Goldstein N
,
Cohen Y
,
Pode-Shakked B
,
Sigalov E
,
Vilensky B
,
Peleg L
,
Anikster Y
.
Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel.
Abstract
Classic galactosemia is an autosomal recessive disorder of galactose metabolism manifesting in the first weeks of life following exposure to a milk-based diet. Despite the benefit of avoidance of lactose, many patients suffer from long-term complications including
neurological deficits and ovarian failure.
To date, over 230 mutations have been described in the GALT gene resulting in galactosemia. Recently, an unusual mutation was characterized causing a 5.5kb deletion, with a relatively high carrier rate in subjects of Ashkenazi Jewish (AJ) descent.
The aim of this study was to estimate the carrier frequency of this mutation in the AJ population in Israel. For this purpose we developed a high-throughput methodology to genotype both normal and deleted alleles using a chip-based matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometer and Multiplex PCR. DNA samples of 760 anonymous AJ subjects were submitted for analysis, subsequently detecting six individuals heterozygous for the GALT deletion mutation, giving a carrier
frequency of 1 in 127 (0.79%). Based on these results, we suggest that the method described here provides a basis for genetic screening and prenatal counseling and can potentially reduce the morbidity and mortality associated with delayed diagnosis of galactosemia in this patient population.
Copyright © 2010 Elsevier Inc. All rights reserved.
PMID: 21059483 [PubMed - as supplied by publisher]
Obstet Gynecol Surv. 2008 May;63(5):334-43.
Fertility and impact of pregnancies on the mother and child in classic galactosemia.
Gubbels CS
,
Land JA
,
Rubio-Gozalbo ME
.
Department of Pediatrics, University Hospital Maastricht, The Netherlands.
Abstract
Despite the high prevalence of premature ovarian failure (POF) and subsequent infertility in galactosemic women, spontaneous pregnancies occur and may not be as rare as is generally assumed. This is important for counseling these women on fertility. The purpose of this review is to assess the occurrence and predicting factors of pregnancy, and to evaluate the impact of pregnancy on the mother's and child's health. The female Dutch galactosemia population (age > 18 years) was studied, and a literature search on articles reporting pregnancy in galactosemic women, published between January 1971 and December 2007, was performed.
Twenty-two galactosemic women were studied. Nine women have tried to conceive, of which 4 were successful. Three mothers were diagnosed with POF before the first pregnancy and/or in between pregnancies. In literature, 50 pregnancy reports were found. In 10 pregnancy reports from the literature, the mother's genotype is known. Four women were homozygous for the Q188R mutation, which equals the incidence of 40-45% of classic galactosemia caused by this mutation.
This study challenges the current opinion that the chance of becoming pregnant is small in classic galactosemia. Despite POF in most galactosemic women, pregnancies do occur. The genotype and GALT-activity do not seem to predict the chance of becoming pregnant, whereas the occurrence of spontaneous menarche might. No evidence for the need of additional check-ups during the pregnancy and puerperium was found. Elevations in galactose-metabolites do occur, but without evidence of clinical impact for the mother or the child, although possible long-term effects have not been thoroughly investigated.
TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to summarize the purported causes and sequelae of galactosemia, explain the possible sequelae of galactosemia, distinguish alterations of the ovary and the hypothalamic-pituitary axis, identify the frequency of pregnancy and the possible outcome of the offspring, and outline dietary management of patients with galactosemia.
PMID: 18419833 [PubMed - indexed for MEDLINE]