MRCP2-2347

MRCP2-2347

You are asked to counsel a middle-aged couple expecting a grandchild. They are both in good health, with no previous medical history. They both come from South East Asia, and there is no family history of birth abnormalities. Physical examination shows no abnormalities. The following investigations were done:

MALE

Haemoglobin (Hb) 117 g/l 135–175 g/l
Mean corpuscular volume (MCV) 70 fl 76–98 fl
Mean cell haemoglobin (MCHb) 19 pg 27–32 pg
Red cell count 5.6 × 1012/l 4.7–6.9 × 1012/l
Haemoglobin electrophoresis normal

FEMALE

Haemoglobin (Hb) 101 g/l 115–155 g/l
Mean corpuscular volume (MCV) 68 fl 76–98 fl
Mean cell haemoglobin (MCHb) 18 pg 27–32 pg
Red cell count 6.0 × 1012/l 4.7–6.9 × 1012/l
Haemoglobin electrophoresis normal

What is the potential risk for the fetus to develop a certain condition?