Table 1 Study characteristics of the included studies
From: Cognitive functioning in patients with classical galactosemia: a systematic review
| Author (year) | Study design | N [P]/[C] | Mean age y:mo (range) | Gender | Criteria for diagnosis | Age of diagnosis /start of diet | Genetic mutation (N) | Clinical outcome (N) | Psychiatric symptoms (N) |
|---|---|---|---|---|---|---|---|---|---|
| Antshel et al. (2004) [19] | Case Control | 25 / 20 | 10:9 (8–14) | 10 females, 15 males | Confirmed by genetic analysis | NR / first week of life | Q188R/Q188R (25) | Special education (14) IQ: 84.3 (SD = 8.3) |
CDI: z = 0.14 (SD = 0.04) ADHD (4): no medication 24 h before NPA |
| Doyle et al. (2010) [21] | Cross-sectional | 28 | 29:3 (15–53) | 20 females, 8 males | Confirmed by very low GALT-activity in leucocytes | Neonatally / NRa | NI | IQ: 88.9 (SD = 16.8) | No psychiatric disorders. |
| Hoffmann et al. (2011) [22] | Cross-sectional | 32 | 21:2 (9:9–37:4) | 12 females, 20 males | Confirmed by GALT activity < 2% and genetic analysis | NR / NR | NR | IQ: 76.2 (SD = 14.8) | NR |
| Iakovou et al. (2018) [26] | Case Report | 1 | 4 | 1 male | Confirmed by absent GALT activity | Neonatally/ Neonatally | NI | IQ: 115 (age of 19) | NR |
| Kaufman et al. (1995) [23] | Cross-sectional | 45 | 4:0–39 | 22 females, 23 males | Confirmed by absence of GALT activity | Neonatally or in infancy / Neonatally or in infancy | NI | Tremor, ataxia and dysmetria (12) | NR |
| Lewis et al. (2012) [25] | Case series | 4 | 7:77:88:59:2 | 3 females, 1 male |
Confirmed by GALT activity < 1.3 units/ml blood and genetic analysis |
5 days / 5 days (3) or birth (1) | Q188R/Q188R (4) | IQ: 118 IQ: 67 IQ: 60IQ: 73 | NR |
|
Lewis et al. (2013) [20] | Case Control | 1 / 3 | 5:7 | 1 male | Confirmed by genetic analysis |
6 days / 6 days | Q188R/Q188R | IQ: within average range | NR |
|
Lewis et al. (2013) [27] | Case Report | 1 | 2:1 | 1 female | Confirmed by GALT activity < 0.01 U/g Hb and genetic analysis |
7 days / 7 days | Q188R/Q188R | Learning disabled IQ = 60 | NR |
| Ng et al. (2003) [28] | Case Report | 1 | 8 | 1 female | Confirmed by GALT activity (0.1–0.3%) and genetic analysis | ± 2–3 weeks / ± 2–3 weeks | Q133R/other | IQ: 123 Normal ovarian function later in life | NR |
| Van Erven et al. (2017) [24] | Cross-sectional | 12 | 17:4 (14:6–21:1) | 9 females, 3 males | Confirmed by GALT activity (0.55%) and/or genetic analysis. | NR / Mean of 11 days (range: 0–35) |
Q188R/Q188R (5) Q188R/other (1) L195P/K229 N (3) W134 fs/unknown (2) Unknown (1) | Special education (9) | NR |
| Waisbren et al. (2012) [15] | Cross-sectional | 27 | 29:10 (18–51) | 13 females, 14 males | Confirmed by absence of GALT activity and genetic analysis. | Mean of 12 days (range: 1–42)/NR |
Q188R/Q188R (12) Q188R/other (12) K285 N/L195P (1) K127Q/deletion (1) Deletion/deletion (1) |
IQ: 89.4 (SD = 19.5) Tremor (11) Ataxia (3) Dysarthria (6) Apraxia (2) | Depression (10) Anxiety (20) |