A newborn baby presented with profuse bleeding from the umbilical stump after birth. Rest of the examination and PT, APTT are within normal limits. Most probable diagnosis is -
Normal PT and APTT exclude option a and c because PT is raised in factor X deficiency and APTT is raised in Von Willebrand disease.
So we are left with Glanzmann's thrombasthenia and Bernard Soulier syndrome.
Both these disorder are platelet function disorders and can result in neonatal bleeding.
Disorders of platelet function produce defects in the formation of a hemostatic plug and thus results in bleeding.
Both are congenital disorders.
There is little to differentiate between these two disorders.
Between these two, Glanzmann's thrombasthenia can present as bleeding since birth.

Glanzmann's thrombasthenia

Glanzmann's thrombasthenia is a rare autosomal recessive disorder.
The disease is characterized by a deficiency of glycoprotein IIb/IIIa which acts as a receptor for fibrinogen.
The disease manifests at birth with increased bleeding from the umbilical cord stump.

a. There is a lifelong mucocutaneous bleeding tendency in the form of epistaxis, ecchymoses and bleeding from the gums.
b. Episodes of G.I. bleeding genitourinary bleeding or post surgery/trauma may occur. However, bleeding episodes decrease with increasing age.
Bernard Soulier syndrome

It is a rare autosomal disorder characterized by mild thrombocytopenia, giant platelets and defective adhesion.
The striking abnormality is giant platelet in peripheral smear.
The membrane abnormality is GPIb-IX-V complex in platelets and megakaryocytes.
Bleeding usually begins at an early age.
There is moderate bleeding in the form of purpuric rash, bruising epistaxis, gingival bleeding and men.

The main lab findings are increased in bleeding time without any coagulation abnormality.
Factor X deficiency
Glanzmann thrombasthenia
Von willebrand disease
Bernard soulier disease