10 oz 7 week old kitten normal?

Hi my kitten is a little boy and he only weighs 278 grams. He is 7 weeks old and his 2 brothers are almost 800 grams each and sister is 700 grams. He doesn't play with them or climb at all. He is always sleeping cuddled up to me or a blanket when his litter goes off to chase toys and things. He is slow at walking. I'm going to take him to the vet soon. Is it normal for him to weigh so little? I was told when he was in his moms tummy that in the X-ray it didn't look like one would make it but he's here and still alive. Here are some photos. Anyone else have a kitten that's 7 weeks and weighs so little? He does eat and I always saw him nursing. He's one of 4 kittens to a first time mom.

his brothers and sister

Another photo of him on my foot. My foot size is 7 girls.

OMG, he is so sweet and tiny! I would definitely get him checked out by the vet, his not moving much is kinda worrisome. He may have heart troubles.  Otherwise as long as he is eating and growing some he should make it! He is beautiful!

Thanks. At vet now. He fell asleep and isn't moving his head much. He just keeps sleeping.

Yeah there is definitely something wrong here.

7 week olds should weigh a good 1 1/2 pounds, 4 week olds about 1 pound.

It is always possible that he is just small, I've had kittens who took until 4 months old to make 2 lbs to be fixed, but usually it's a defect or some reason for this small size.

What a doll!!

He is being hospitalized for the night. His body temp is very low and isn't moving much. He has a heart murmur and possible infection. I'm paying he will be ok. It's not cheap but I'm paying what ever it takes to make him better. He hopefully gets to come home tomorrow.

How is he doing today? 

Unfortunately he needed to be let go of as his gums turned blue and he was put on oxygen. I lost him at 505 pm today. Very heartbroken.

I'm so sorry. He had a home and a happy life for the short time he was here. Not many kittens ever have that chance. Run free little kitten.

I'm so sorry

Run free, little one

How terribly sad, I'm so sorry to hear this