Cynthia S. Gubbels

The adult galactosemic phenotype

BackgroundClassic galactosemia is an autosomal recessive disorder due to galactose-1-phosphate uridyltransferase (GALT) deficiency. Newborn screening and early treatment do not completely prevent tremor, speech deficits, and diminished IQ in both sexes and premature ovarian insufficiency (POI) in women. Data on how individuals with galactosemia fare as adults will improve our ability to predict disease progression.MethodsThirty-three adults (mean age = 32.6 ± 11.7 years; range = 18–59) with classic galactosemia, confirmed by genotype and undetectable GALT enzyme activity, were evaluated. Analyses assessed associations among age, genotype, clinical features and laboratory measures.ResultsThe sample included 17 men and 16 women. Subjects exhibited cataracts (21%), low bone density (24%), tremor (46%), ataxia (15%), dysarthria (24%), and apraxia of speech (9%). Subjects reported depression (39%) and anxiety (67%). Mean full scale IQ was 88 ± 20, (range = 55–122). All subjects followed a dairy-free diet and 75–80% reported low intake of calcium and vitamin D. Mean height, weight and body mass were within established norms. All female subjects had been diagnosed with POI. One woman and two men had had children. Logistic regression analyses revealed no associations between age, genotype or gender with IQ, tremor, ataxia, dysarthria, apraxia of speech or anxiety. Each 10- year increment of age was associated with a twofold increase in odds of depression.ConclusionsTaken together, these data do not support the hypothesis that galactosemia is a progressive neurodegenerative disease. However, greater attention to depression, anxiety, and social relationships may relieve the impact of this disorder in adults.

Gonadal function in male and female patients with classic galactosemia

BACKGROUND Hypergonadotropic hypoestrogenic infertility is the most burdensome complication for females suffering from classic galactosemia. In contrast, male gonadal function seems less affected. The underlying mechanism is not understood and several pathogenic mechanisms have been proposed. Timing of the lesion, prenatal or chronic post-natal, or a combination of both are not yet clear. METHODS This review focuses on gonadal function in males and females, ovarian imaging and histology in this disease. It is based on the literature known to the authors and a Pubmed search using the keywords galactosemia, GALT deficiency, (premature) ovarian failure/insufficiency/dysfunction, testicular function, gonadotrophins, FSH, LH (published between January 1971 and April 2009). RESULTS Male gonads are less affected, boys spontaneously reach puberty, although onset can be delayed. Semen quality has not been extensively studied. Several affected males are known to have fathered a child. Female gonads are invariably affected, although to a varied extent (hypergonadotropic hypoestrogenic ovarian dysfunction). Intriguingly, FSH is often already increased in infancy. Imaging usually shows hypoplastic and streak-like ovaries. Histological findings in some cases reveal the presence of morphologically normal but decreased numbers of primordial follicles, with the absence of intermediate and Graafian follicles. CONCLUSION Gonads in males seem less affected than in females who exhibit hypergonadotropic hypoestrogenic subfertility. FSH can be elevated in infancy, and ovarian histology sometimes shows the presence of normal primordial follicles with absence of intermediate and Graafian follicles. These findings are similar to other genetic diseases primarily affecting the ovary.

Ovarian function in girls and women with GALT-deficiency galactosemia

Primary or premature ovarian insufficiency (POI) is the most common long-term complication experienced by girls and women with classic galactosemia; more than 80% and perhaps more than 90% are affected despite neonatal diagnosis and careful lifelong dietary restriction of galactose. In this review we explore the complexities of timing and detection of galactosemia-associated POI and discuss potential underlying mechanisms. Finally, we offer recommendations for follow-up care with current options for intervention.

Fertility and impact of pregnancies on the mother and child in classic galactosemia

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 mothers and childs 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 mothers 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.

FSH isoform pattern in classic galactosemia

Female classic galactosemia patients suffer from primary ovarian insufficiency (POI). The cause for this long-term complication is not fully understood. One of the proposed mechanisms is that hypoglycosylation of complex molecules, a known secondary phenomenon of galactosemia, leads to FSH dysfunction. An earlier study showed less acidic isoforms of FSH in serum samples of two classic galactosemia patients compared to controls, indicating hypoglycosylation. In this study, FSH isoform patterns of five classic galactosemia patients with POI were compared to the pattern obtained in two patients with a primary glycosylation disorder (phosphomannomutase-2-deficient congenital disorders of glycosylation, PMM2-CDG) and POI, and in five postmenopausal women as controls. We used FPLC chromatofocussing with measurement of FSH concentration per fraction, and discovered that there were no significant differences between galactosemia patients, PMM2-CDG patients and postmenopausal controls. Our results do not support that FSH dysfunction due to a less acidic isoform pattern because of hypoglycosylation is a key mechanism of POI in this disease.

Pregnancy in classic galactosemia despite undetectable anti-Müllerian hormone

OBJECTIVE To report a pregnancy in a patient with classic galactosemia despite signs of no ovarian reserve to draw attention to the limited predictive value of ovarian reserve tests in these patients. DESIGN Case report. SETTING Secondary and tertiary care center. PATIENT(S) A patient with classic galactosemia with premature ovarian failure and two previous pregnancies. INTERVENTION(S) Exogenous FSH ovarian reserve test and anti-Müllerian hormone (AMH) measurement. MAIN OUTCOME MEASURE(S) 17beta-Estradiol response, AMH level. RESULT(S) Pregnancy despite undetectable AMH (<0.1 microg/L) and no E(2) response (exogenous FSH ovarian reserve test). CONCLUSION(S) Fluctuating premature ovarian failure makes fertility counseling of patients with classic galactosemia difficult. Commonly used ovarian function and reserve tests seem to have no significance.

Fertility preservation in female classic galactosemia patients.

Almost every female classic galactosemia patient develops primary ovarian insufficiency (POI) as a diet-independent complication of the disease. This is a major concern for patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The unique pathophysiology of classic galactosemia with a severely reduced follicle pool at an early age requires an adjusted approach. In this article recommendations for physicians based on current knowledge concerning galactosemia and fertility preservation are made. Fertility preservation is only likely to be successful in very young prepubertal patients. In this group, cryopreservation of ovarian tissue is currently the only available technique. However, this technique is not ready for clinical application, it is considered experimental and reduces the ovarian reserve. Fertility preservation at an early age also raises ethical questions that should be taken into account. In addition, spontaneous conception despite POI is well described in classic galactosemia. The uncertainty surrounding fertility preservation and the significant chance of spontaneous pregnancy warrant counseling towards conservative application of these techniques. We propose that fertility preservation should only be offered with appropriate institutional research ethics approval to classic galactosemia girls at a young prepubertal age.

Psychosocial developmental milestones in men with classic galactosemia

Patients with classic galactosemia suffer from several long term effects of their disease. Research in a group of mainly female patients has shown that these patients may also have a developmental delay with regard to their social aptitude. To study if male galactosemia patients achieve psychosocial developmental milestones more slowly than male peers from the general Dutch population, we assessed their development with the Course of Life Questionnaire (CoLQ). A total of 18 male galactosemia patients participated in this study (response rate 69%): 11 Dutch patients and seven American patients. We found severe delays in the social and psychosexual scales of this questionnaire, but not on the autonomy axis. These results are comparable to an earlier study with a limited number of male patients. The observed delays could be secondary to less developed social skills, cognitive dysfunction, or disrupted language development. We strongly recommend screening of galactosemia patients for developmental delays, to ensure early intervention through social skills training.

BRAT1 mutations present with a spectrum of clinical severity

Mutations in BRAT1, encoding BRCA1‐associated ATM activator 1, are associated with a severe phenotype known as rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL; OMIM # 614498), characterized by intractable seizures, hypertonia, autonomic instability, and early death. We expand the phenotypic spectrum of BRAT1 related disorders by reporting on four individuals with various BRAT1 mutations resulting in clinical severity that is either mild or moderate compared to the severe phenotype seen in RMFSL. Representing mild severity are three individuals (Patients 1–3), who are girls (including two sisters, Patients 1–2) between 4 and 10 years old, with subtle dysmorphisms, intellectual disability, ataxia or dyspraxia, and cerebellar atrophy on brain MRI; additionally, Patient 3 has well‐controlled epilepsy and microcephaly. Representing moderate severity is a 15‐month‐old boy (Patient 4) with severe global developmental delay, refractory epilepsy, microcephaly, spasticity, hyperkinetic movements, dysautonomia, and chronic lung disease. In contrast to RMFSL, his seizure onset occurred later at 4 months of age, and he is still alive. All four of the individuals have compound heterozygous BRAT1 mutations discovered via whole exome sequencing: c.638dupA (p.Val214Glyfs*189); c.803+1G>C (splice site mutation) in Patients 1–2; c.638dupA (p.Val214Glyfs*189); c.419T>C (p.Leu140Pro) in Patient 3; and c.171delG (p.Glu57Aspfs*7); c.419T>C (p.Leu140Pro) in Patient 4. Only the c.638dupA (p.Val214Glyfs*189) mutation has been previously reported in association with RMFSL. These patients illustrate that, compared with RMFSL, BRAT1 mutations can result in both moderately severe presentations evident by later‐onset epilepsy and survival past infancy, as well as milder presentations that include intellectual disability, ataxia/dyspraxia, and cerebellar atrophy.

Increased Survival and Partly Preserved Cognition in a Patient With ACO2-Related Disease Secondary to a Novel Variant

ACO2 encodes aconitase 2, catalyzing the second step of the tricarboxylic acid. To date, there are only 6 reported families with 5 unique ACO2 mutations. Affected individuals can develop intellectual disability, epilepsy, brain atrophy, hypotonia, ataxia, optic atrophy, and retinal degeneration. Here, we report an 18-year-old boy with a novel ACO2 variant discovered on whole-exome sequencing. He presented with childhood-onset ataxia, impaired self-help skills comparable to severe-profound intellectual disability, intractable epilepsy, cerebellar atrophy, peripheral neuropathy, optic atrophy, and pigmentary retinopathy. His variant is the sixth unique ACO2 mutation. In addition, compared to mild cases (isolated optic atrophy) and severe cases (infantile death), our patient may be moderately affected, evident by increased survival and some preserved cognition (ability to speak full sentences and follow commands), which is a novel presentation. This case expands the disease spectrum to include increased survival with partly spared cognition.